Tube pump

ABSTRACT

A tube pump ( 1 A) of the present invention is provided with a main body ( 2 ) to which a tube ( 100 ) is attached, a rotor ( 5 ), an oscillator ( 6 ) located so as to touch an outer circumferential face of the rotor ( 5 ), and a plurality of rollers ( 10 ) mounted to the rotor ( 5 ) for pressurizing and thereby squeezing the tube ( 100 ). The oscillator ( 6 ) is essentially shaped like a rectangular plate, and is formed by laminating an electrode, a piezoelectric element, and a reinforcing plate. When an alternating current voltage is applied to the piezoelectric element, the oscillator ( 6 ) oscillates longitudinally in the direction of the length at minute amplitude as the piezoelectric element expands and contracts. The rotor ( 5 ) receives a frictional force and a pressing force from a convex portion ( 66 ) when the oscillator ( 6 ) expands, and the rotor ( 5 ) rotates as it repetitively receives the frictional force and the pressing force. Consequently, it is possible to provide a tube pump having a simple structure, and hence, having an advantage in reducing the size, particularly the thickness thereof.

TECHNICAL FIELD

[0001] The present invention relates to a tube pump.

BACKGROUND ART

[0002] A tube pump that feeds a fluid within an elastic tube bysqueezing the tube has been known and used extensively in, for example,medical equipment, printers, etc.

[0003] The tube pump generally includes a rotor, a motor forrotationally driving the rotor, and a plurality of rollers mounted tothe rotor. These rollers pressurize a tube placed along the outercircumference of the rotor at a portion thereof to be sealed as therotor rotates, whereby a fluid is fed forward.

[0004] The conventional tube pump, however, includes a largerotor-driving motor, and therefore, has a problem that it is difficultto reduce the size, particularly the thickness thereof. Also, theconventional tube pump has a problem that electromagnetic noises of themotor may possibly affect other equipment.

[0005] In addition, the conventional tube pump has a problem that thetube repetitively pressurized at a portion thereof to be sealed by therollers deteriorates fast and has a short lifespan.

[0006] Further, the conventional tube pump has a problem that a segmentof the tube is kept pressed by the rollers while not in use, so that thesegment will have a flattening habit or deforming habit. Once the tubehas the flattening habit, it results in adverse effects as follows:deterioration takes place at the segment; a quantity of discharge fromthe tube pump becomes unstable; and a desired quantity of dischargecannot be obtained. Hence, the conventional tube pump has aninconvenience that, for example, it cannot be stored over a long periodafter it is manufactured.

SUMMARY OF THE INVENTION

[0007] The object of the present invention is to provide a tube pumphaving a simple structure, and hence, having an advantage in reducingthe size, particularly the thickness thereof.

[0008] In order to achieve the above object, the present inventionrelates to a tube pump, characterized by including:

[0009] a main body having an attachment portion to which an elastic tubeis attached;

[0010] a rotor mounted rotatably with respect to the main body;

[0011] a plurality of pressurizing portions, provided to the rotor, forpressurizing a segment of the tube;

[0012] a driven member for moving in association with the rotor; and

[0013] at least one oscillator located so as to touch the driven memberand having a piezoelectric element,

[0014] wherein the oscillator oscillates when an alternating currentvoltage is applied to the piezoelectric element and drives the drivenmember by repetitively applying a force to the driven member by means ofoscillations, thereby rotating the rotor.

[0015] According to this arrangement, it is possible to provide a tubepump having a simple structure, and hence, having an advantage inreducing the size, particularly the thickness thereof.

[0016] Also, it is preferable that the driven member is formedintegrally with or fixed to the rotor.

[0017] According to this arrangement, not only can the size and thethickness be further reduced, but also the structure can be extremelysimple.

[0018] Also, it is preferable that the oscillator is located so as totouch the driven member along a direction of a rotational axis of therotor.

[0019] According to this arrangement, the size can be further reduced.

[0020] Also, it is preferable that the oscillator is located so as totouch the driven member along a radius direction of the rotor.

[0021] According to this arrangement, it is possible to drive the rotorto rotate more smoothly in a reliable manner.

[0022] Also, it is preferable that the oscillator is located so as totouch the driven member from an outer circumference side of the rotor.

[0023] According to this arrangement, it is possible to drive the rotorto rotate more smoothly in a reliable manner.

[0024] Also, it is preferable that the oscillator is located so as totouch the driven member from an inner circumference side of the rotor.

[0025] According to this arrangement, not only can the rotor be drivento rotate more smoothly in a reliable manner, but also the size can befurther reduced.

[0026] Also, it is preferable that the driven member rotates the rotorthrough a rotational force transmission mechanism.

[0027] According to this arrangement, it is possible to heighten adegree of freedom as to where the oscillator is located.

[0028] Also, it is preferable that the rotational force transmissionmechanism is a speed changing unit.

[0029] According to this arrangement, it is possible to adjust a fluidfeeding speed by changing the rotational speed of the rotor.

[0030] Also, it is preferable that the oscillator is positioned, almostentirely, on an inside of an outermost radius of the rotor.

[0031] According to this arrangement, the size can be further reduced.

[0032] Also, it is preferable that the oscillator is positioned, almostentirely, within a space as thick as the rotor in a direction of arotational axis of the rotor.

[0033] According to this arrangement, the thickness can be furtherreduced.

[0034] Also, it is preferable that the driven member is provided with aslot, and the oscillator touches an inner face of the slot.

[0035] According to this arrangement, it is possible to prevent thetouching position of the oscillator with respect to the rotor from beingshifted, thereby reducing losses of a driving force.

[0036] Also, it is preferable that the oscillator is of a shape having alonger direction and a shorter direction.

[0037] According to this arrangement, it is possible to drive the rotorat higher efficiency.

[0038] Also, it is preferable that a vicinity of an end portion of theoscillator in a direction of length touches the driven member.

[0039] According to this arrangement, it is possible to drive the rotorat higher efficiency.

[0040] Also, it is preferable that the oscillator is shaped like aplate.

[0041] According to this arrangement, it is possible to drive the rotorat higher efficiency.

[0042] Also, it is preferable that the oscillator is almost shaped likea rectangle.

[0043] According to this arrangement, it is possible to drive the rotorat higher efficiency.

[0044] Also, it is preferable that the oscillator is located in anorientation substantially in parallel with the rotor.

[0045] According to this arrangement, the thickness can be furtherreduced.

[0046] Also, it is preferable that the tube pump further includes an armportion provided so as to protrude from the oscillator, and theoscillator is supported by the arm portion.

[0047] According to this arrangement, it is possible to drive the rotorat higher efficiency.

[0048] Also, it is preferable that more than one oscillator is provided.

[0049] According to this arrangement, the size of each oscillator can befurther reduced.

[0050] Also, it is preferable that the pressurizing portions areprovided immovably with respect to the rotor.

[0051] According to this arrangement, the structure can be furthersimplified.

[0052] Also, it is preferable that the pressurizing portions areprovided rotatably with respect to the rotor.

[0053] According to this arrangement, it is possible to allow the rotorto rotate more smoothly, thereby making it possible to feed a fluid moresmoothly.

[0054] Also, it is preferable that the pressurizing portions are rollerssupported rotatably about their respective rotational axes in adirection substantially along a rotational axis of the rotor.

[0055] According to this arrangement, it is possible to allow the rotorto rotate more smoothly, thereby making it possible to feed a fluid moresmoothly.

[0056] Also, it is preferable that the pressurizing portions are rollerssupported rotatably about their respective rotational axes in adirection intersecting with a rotational axis of the rotor at nearlyright angles.

[0057] According to this arrangement, it is possible to allow the rotorto rotate more smoothly, thereby making it possible to feed a fluid moresmoothly.

[0058] Also, it is preferable that the pressurizing portions are ballsrotatable in an arbitrary direction.

[0059] According to this arrangement, it is possible to allow the rotorto rotate more smoothly, thereby making it possible to feed a fluid moresmoothly, while the structure can be further simplified.

[0060] Also, it is preferable that the pressurizing portions pressurizethe tube at a portion thereof to be sealed along a radius direction ofthe rotor.

[0061] According to this arrangement, it is possible to allow the rotorto rotate more smoothly, thereby making it possible to feed a fluid moresmoothly.

[0062] It is preferable that the pressurizing portions pressurize thetube at a portion thereof to be sealed along a direction of a rotationalaxis of the rotor.

[0063] According to this arrangement, the size can be further reduced.

[0064] Also, it is preferable that an arc portion of the tube attachedto the attachment portion is positioned on an inside of an outermostradius of the rotor.

[0065] According to this arrangement, the size can be further reduced.

[0066] Also, it is preferable that the main body includes a touchingportion for touching any of the pressurizing portions present at aposition for not pressurizing the tube.

[0067] According to this arrangement, it is possible to allow the rotorto rotate more smoothly, thereby making it possible to feed a fluid moresmoothly.

[0068] Also, it is preferable that the main body supports the rotor fromone side.

[0069] According to this arrangement, the thickness can be furtherreduced.

[0070] Also, it is preferable that the tube pump further includes aflexible plate member provided in close proximity to the tube attachedto the attachment portion, and the pressurizing portions pressurize thesegment of the tube at a portion thereof to be sealed through the platemember.

[0071] According to this arrangement, the lifespan of the tube can beextended.

[0072] Also, it is preferable that the plate member is provided almostacross the segment of the tube attached to the attachment portionpressurized at a portion thereof to be sealed by the pressurizingportions.

[0073] According to this arrangement, the lifespan of the tube can befurther extended.

[0074] Also, it is preferable that the plate member is provided in adisplaceable manner in a thickness direction thereof.

[0075] According to this arrangement, the lifespan of the tube can beextended.

[0076] Also, it is preferable that the plate member is provided so asnot to be displaced in an in-plane direction thereof.

[0077] According to this arrangement, the lifespan of the tube can beextended.

[0078] Also, it is preferable that the plate member is provided in adetachable/attachable manner with respect to the main body.

[0079] According to this arrangement, it is possible to replace theplate member with a new one when it is deteriorated or damaged.

[0080] Also, it is preferable that the tube pump further includesdisplacement quantity regulating means for regulating the plate memberso as not to be displaced over a certain limit.

[0081] According to this arrangement, the lifespan of the tube can befurther extended.

[0082] Also, it is preferable that at least one of the plurality ofpressurizing portions is allowed to move with respect to the rotor in apredetermined movable range.

[0083] According to this arrangement, it is possible to prevent the tubefrom having a flattening habit or being blocked due to adhesion of theinner wall while not in use in a reliable manner.

[0084] Also, it is preferable that the plurality of pressurizingportions are able to go into a state that none of the plurality ofpressurizing portions is pressurizing the tube while the rotor is atrest, and when the rotor starts to rotate in this state, the movablepressurizing portion moves relatively with respect to the rotor withinthe movable range, so that, in a steady rotation state of the rotor, theplurality of pressurizing portions go into a state that the plurality ofpressurizing portions are placed at positions where at least one of theplurality of pressurizing portions pressurizes the tube at a portionthereof to be sealed regardless of a rotational position of the rotor.

[0085] According to this arrangement, it is possible to prevent the tubefrom having a flattening habit or being blocked due to adhesion of theinner wall while not in use without performing any special manipulationor the like, thereby achieving enhanced convenience.

[0086] Also, it is preferable that the movable pressurizing portion isallowed to move in a circumferential direction of the rotor within atleast a part of the movable range.

[0087] According to this arrangement, it is possible to attain theaforementioned advantages with a simple structure.

[0088] It is preferable that the plurality of pressurizing portions areplaced along a circumferential direction of the rotor at nearlyequiangular intervals in a steady rotation state of the rotor.

[0089] According to this arrangement, it is possible to feed a fluidmore smoothly.

[0090] Also, it is preferable that the movable pressurizing portion isallowed to move along a slot or a window formed in the rotor.

[0091] According to this arrangement, it is possible to attain theaforementioned advantages with a simple structure.

[0092] Also, it is preferable that the pressurizing portions are convexportions protruding from the rotor.

[0093] According to this arrangement, it is possible to attain theaforementioned advantages with a simple structure.

[0094] Also, it is preferable that:

[0095] the pressurizing portions are rollers rotatable about theirrespective rotational axes in a direction intersecting with a rotationalaxis of the rotor at nearly right angles; and

[0096] the movable roller is provided with a regulating member forregulating an orientation of the movable roller so that the rotationalaxis of the movable roller intersects with the rotational axis of therotor at nearly right angles.

[0097] According to this arrangement, it is possible to allow the rotorto rotate more smoothly, thereby making it possible to feed a fluid moresmoothly.

[0098] Also, it is preferable that:

[0099] the pressurizing portions are rollers rotatable about theirrespective rotational axes in a direction substantially along arotational axis of the rotor;

[0100] the tube pump further includes,

[0101] a pressure-applying rotor mounted coaxially with the rotor, and

[0102] a pressing portion, provided to the rotor, for pressing themovable roller in a rotational direction of the rotor; and

[0103] the movable roller is not supported by the rotor, and in a steadyrotation state of the rotor, the movable roller rotates while touchingthe pressure-applying rotor and the pressing portion.

[0104] According to this arrangement, not only can an extremely smoothoperation be achieved, but also there can be offered an advantage infurther reducing the thickness.

BRIEF DESCRIPTION OF THE DRAWINGS

[0105]FIG. 1 is a cross-sectional plan view showing a first embodimentof a tube pump of the present invention.

[0106]FIG. 2 is a cross-sectional side view showing the first embodimentof the tube pump of the present invention.

[0107]FIG. 3 is a perspective view showing an oscillator in the tubepump shown in FIGS. 1 and 2.

[0108]FIG. 4 is a plan view showing flex oscillations of the oscillatorin the tube pump shown in FIGS. 1 and 2.

[0109]FIG. 5 is a plan view showing elliptical motion of a convexportion of the oscillator in the tube pump shown in FIGS. 1 and 2.

[0110]FIG. 6 is a cross-sectional side view showing a second embodimentof the tube pump of the present invention.

[0111]FIG. 7 is a plan view showing a third embodiment of the tube pumpof the present invention.

[0112]FIG. 8 is a view showing a plane indicated by an arrow Q of FIG.7.

[0113]FIG. 9 is a partially cutaway plan view showing a fourthembodiment of the tube pump of the present invention.

[0114]FIG. 10 is a cross-sectional side view taken along the plane ofthe line Z-Z of FIG. 9.

[0115]FIG. 11 is a cross-sectional side view showing a fifth embodimentof the tube pump of the present invention.

[0116]FIG. 12 is a cross-sectional side view showing a sixth embodimentof the tube pump of the present invention.

[0117]FIG. 13 is a cross-sectional side view showing a seventhembodiment of the tube pump of the present invention.

[0118]FIG. 14 is a partially cutaway plan view showing an eighthembodiment of the tube pump of the present invention.

[0119]FIG. 15 is a cross-sectional side view taken along the plane ofthe line U-U of FIG. 14.

[0120]FIG. 16 is a plan view showing a ninth embodiment of the tube pumpof the present invention.

[0121]FIG. 17 is a cross-sectional side view taken along the plane ofthe line V-V of FIG. 16.

[0122]FIG. 18 is a cross-sectional side view showing a tenth embodimentof the tube pump of the present invention.

[0123]FIG. 19 is a plan view showing an eleventh embodiment of the tubepump of the present invention.

[0124]FIG. 20 is a cross-sectional side view taken along the plane ofthe line W-W of FIG. 19.

[0125]FIG. 21 is a cross-sectional plan view explaining a positionalrelation of balls with respect to a rotor and a tube in the tube pumpshown in FIGS. 19 and 20.

[0126]FIG. 22 is a cross-sectional plan view explaining a positionalrelation of the balls with respect to the rotor and the tube in the tubepump shown in FIGS. 19 and 20.

[0127]FIG. 23 is a cross-sectional side view showing a twelfthembodiment of the tube pump of the present invention.

[0128]FIG. 24 is a cross-sectional plan view explaining a positionalrelation of pressurizing portions with respect to a rotor and a tube inthe tube pump shown in FIG. 23.

[0129]FIG. 25 is a cross-sectional plan view explaining a positionalrelation of the pressurizing portions with respect to the rotor and thetube in the tube pump shown in FIG. 23.

[0130]FIG. 26 is a partially cutaway plan view showing a thirteenthembodiment of the tube pump of the present invention.

[0131]FIG. 27 is a cross-sectional side view showing the vicinity of arotor in the tube pump shown in FIG. 26.

[0132]FIG. 28 is a cross-sectional development elevation showing arotational force transmission mechanism in the tube pump shown in FIG.26.

[0133]FIG. 29 is a cross-sectional plan view explaining a positionalrelation of rollers with respect to a rotor and a tube in the tube pumpshown in FIG. 26.

[0134]FIG. 30 is a cross-sectional plan view explaining a positionalrelation of the rollers with respect to the rotor and the tube in thetube pump shown in FIG. 26.

[0135]FIG. 31 is a plan view showing a fourteenth embodiment of the tubepump of the present invention.

[0136]FIG. 32 is a cross-sectional side view showing the vicinity of arotor in the tube pump shown in FIG. 31.

[0137]FIG. 33 is a cross section showing a mount portion for a movableroller in the tube pump shown in FIG. 31.

BEST MODE FOR CARRYING OUT THE INVENTION

[0138] The following description will describe in detail a tube pump ofthe present invention based on preferred embodiments shown in theaccompanying drawings.

[0139] (First Embodiment)

[0140]FIGS. 1 and 2 are respectively a cross-sectional plan view and across-sectional side view showing a first embodiment of the tube pump ofthe present invention. FIG. 3 is a perspective view showing anoscillator in the tube pump shown in FIGS. 1 and 2. FIG. 4 is a planview showing flex oscillations of the oscillator in the tube pump shownin FIGS. 1 and 2. FIG. 5 is a plan view showing elliptical motion of aconvex portion of the oscillator in the tube pump shown in FIGS. 1 and2. FIG. 1 is a cross section taken along the line Y-Y of FIG. 2 and FIG.2 is a cross section taken along the line X-X of FIG. 1. In thefollowing description, the upper side and the lower side of FIG. 2 areassumed to be “top” and “bottom”, respectively.

[0141] A tube pump 1A shown in FIGS. 1 and 2 is provided with a mainbody 2 having an attachment portion 210 to which an elastic tube 100 isattached, a rotor 5 mounted rotatably with respect to the main body 2,an oscillator 6 for rotationally driving the rotor 5, and a plurality ofrollers 10 mounted to the rotor 5. The following description willdescribe an arrangement of each component.

[0142] As shown in FIG. 2, the main body 2 is composed of a base 21 anda cover 22 covering the upper side of the base 21. A space 23 foraccommodating the rotor 5 and the tube 100 is defined in the interior ofthe main body 2. In the present embodiment, the base 21 and the cover 22together form an enclosure.

[0143] The base 21 includes a bottom plate 211 and a wall portion 212erected upward from the bottom plate 211. The bottom plate 211 isprovided with an axial hole 213 into which a rotor rotational axis 52described below is inserted.

[0144] The cover 22 is essentially shaped like a plate and is fixed tothe upper side of the base 21. The cover 22 is provided with an axialhole 221 into which the rotor rotational axis 52 is inserted. The space23 is defined by being surrounded with the bottom plate 211, the wallportion 212, and the cover 22.

[0145] As shown in FIG. 1, at least a part of the inner face of the wallportion 212 is formed arc-wise. In other words, an inner circumferentialface 215 of the wall portion 212 in the right half of FIG. 1 is curvedarc-wise.

[0146] The wall portion 212 in the left side of FIG. 1 is provided withslots 216 and 217, each of which communicates with the outside of themain body 2 from the space 23. The slot 216 is positioned at the upperside of FIG. 1 and the slot 217 is positioned at the lower side of FIG.1.

[0147] In the present embodiment, an inner circumferential face 218 ofthe wall portion 212 between the slot 216 and the slot 217 is alsoformed arc-wise. However, the inner circumferential face 218 does nothave to be formed arc-wise, and for example, it may be formed linearly.

[0148] The tube 100 is attached to the main body 2 arranged as abovealong the slot 216, the inner circumferential face 215, and the slot 217essentially in the shape of a letter U. In other words, the tube 100includes an arc portion 103 placed along the inner circumferential face215, an upstream portion 101 extending to the outside of the main body 2from one end of the arc portion 103 via the slot 216, and a downstreamportion 102 extending to the outside of the main body 2 from the otherend of the arc portion 103 via the slot 217.

[0149] As has been described, the attachment portion 210 for the tube100 includes the inner circumferential face 215 and the slots 216 and217.

[0150] The tube 100 has elasticity, that is, flexibility andrestorability. Hence, when pressed by the rollers 10 described below,the tube 100 goes into a blocked state (the state shown in the left sideof FIG. 2), and when the pressing is removed, the tube 100 restores tothe original state (the state shown in the right side of FIG. 2).

[0151] The rotor 5 is mounted in the space 23 of the main body 2concentrically with the inner circumferential face 215. The rotor 5includes a rotor main body 51, the rotor rotational axis 52 installed soas to extend vertically from the central portion of the rotor main body51, and an annular ring 53 fixed to the outer circumferential portion ofthe rotor main body 51 by press-fit, for example.

[0152] The rotor main body 51 is essentially shaped like a disc. Themajor diameter of the rotor 5 is less than the minor diameter of theinner circumferential face 215, that is, twice the radius of curvatureof the inner circumferential face 215, thereby leaving a clearancebetween the outer circumference of the rotor 5 and the innercircumferential face 215.

[0153] As shown in FIG. 2, the top end portion of the rotor rotationalaxis 52 is inserted into the axial hole 221 and supported rotatably withrespect to the cover 22 through a bearing 11. Also, the bottom endportion of the rotor rotational axis 52 is inserted into the axial hole213 and supported rotatably with respect to the base 21 through abearing 12. In short, the rotor 5 is mounted rotatably with respect tothe main body 2.

[0154] The oscillator 6, which will be described below, touches theouter circumferential face of the rotor 5, that is, the outercircumferential face of the ring 53, so that when the oscillator 6oscillates, the ring 53 repetitively receives a frictional force and apressing force from the oscillator 6, thereby being driven to rotate ina clockwise direction of FIG. 1. In short, the ring 53 serves as adriven member driven by the oscillator 6.

[0155] Also, as shown in FIG. 2, in the present embodiment, a slot 531is formed at the outer circumference of the ring 53 along thecircumferential direction, and the oscillator 6 touches an inner face532 of the slot 531. This arrangement makes it possible to prevent thetouching position of the oscillator 6 from being shifted vertically withrespect to the ring 53. Also, because the cross section of the innerface 532 is formed arc-wise, even if the touching position of theoscillator 6 with respect to the ring 53 slightly shifts vertically, theoscillator 6 and the ring 53 maintain their touching state, therebylosing no driving force.

[0156] Two roller rotational axes 54 are installed so as to protrudedownward from the rotor main body 51. In short, the roller rotationalaxes 54 are installed in parallel with the rotor rotational axis 52.

[0157] The rollers 10, which block the tube 100 by pressing, that is,serve as pressurizing portions for pressurizing the tube 100, aremounted on the respective roller rotational axes 54 throughunillustrated bearings. The rollers 10 are positioned at the lower sideof the rotor main body 51, and mounted rotatably about their respectiveroller rotational axes 54, that is, allowed to rotate on their axes.Also, the rollers 10 rotate, namely, revolve about the rotor rotationalaxis 52 as the rotor 5 rotates.

[0158] The rollers 10 are formed essentially cylindrically. The rollers10 are positioned on the inside of the tube 100 placed in the shape of aletter U, and positioned nearly as high as the tube 100 in the verticaldirection.

[0159] Also, in the present embodiment, when viewed in a plane shown inFIG. 1, the rollers 10 are mounted at a positional relation so that theyare essentially inscribed in the rotor main body 51 at the outermostedge thereof. In other words, when viewed in a plane shown in FIG. 1,the rollers 10 are mounted at positions so that they do not extendoutside of the rotor 5.

[0160] As shown in FIG. 1, in the present embodiment, the two rollers 10are mounted along the circumferential direction of the rotor 5 atequiangular intervals, that is, at intervals of 180°. In the presentinvention, three or more pressurizing portions like the rollers 10 maybe mounted to the rotor 5. In this case, it is preferable that thepressurizing portions like the rollers 10 are also mounted along thecircumferential direction of the rotor 5 at equiangular intervals.

[0161] When the rotor 5 rotates in a clockwise direction of FIG. 1, atleast one of the two rollers 10 squeezes the arc portion 103 of the tube100 along the rotational direction of the rotor 5 while pressurizing thearc portion 103 with the inner circumferential face 215, whereby a fluidwithin the tube 100 is fed forward. Consequently, the fluid is taken infrom the upstream portion 101 of the tube 100 and discharged from thedownstream portion 102 of the tube 100.

[0162] As has been described, in the present embodiment, the rollers 10press the tube 100 from the inner circumference side to the outercircumference side in the radius direction of the rotor 5. Consequently,the direction of a reactive force that the rotor 5 receives from the arcportion 103 of the tube 100 becomes nearly perpendicular to the rotorrotational axis 52, which prevents the rotor 5 from tilting, therebyallowing the rotor 5 to rotate more smoothly in a reliable manner.

[0163] Also, in the present embodiment, because the rollers 10 squeezethe tube 100 while they are rotating on their axes, they do not pull thetube 100 in the direction of revolution, which prevents the tube 100from being shifted with respect to the main body 2.

[0164] As shown in FIGS. 1 and 2, the base 21 of the main body 2 isprovided with the oscillator 6 for rotationally driving the rotor 5. Theoscillator 6 is small and thin in comparison with a typical motor or thelike. According to the present invention, by using the oscillator 6 inrotationally driving the rotor 5, it is possible to reduce the size,particularly the thickness of the entire tube pump 1A. An explanation ofthe oscillator 6 will be given in the following.

[0165] As shown in FIG. 3, the oscillator 6 is essentially shaped like arectangular plate. The oscillator 6 is composed of a plate electrode 61,a plate piezoelectric element 62, a reinforcing plate 63, a platepiezoelectric element 64, and a plate electrode 65, which are laminatedsequentially in this order from the upper side of FIG. 3. The thicknessdirection is emphasized in the illustration of FIG. 3.

[0166] Each of the piezoelectric elements 62 and 64 is shaped like arectangle and expands and contracts in the length direction when avoltage is applied. A forming material of the piezoelectric elements 62and 64 is not especially limited, and lead zirconate titanate (PZT),crystal, lithium niobate, barium titanate, lead titanate, leadmeta-niobate, polyvinylidene fluoride, lead zinc niobate, lead scandiumniobate, etc. are available.

[0167] The piezoelectric elements 62 and 64 are fixed to both faces ofthe reinforcing plate 63, respectively. The reinforcing plate 63 isfurnished with a function of reinforcing the entire oscillator 6, andtherefore, prevents the oscillator 6 from being damaged by anexcessively large amplitude, an external force, etc. A forming materialof the reinforcing plate 63 is not especially limited, but metalmaterials of various kinds including, for example, stainless steel,aluminum, aluminum alloy, titanium, titanium alloy, copper, copper-basedalloy, etc. are preferable.

[0168] The reinforcing plate 63 is preferably thinner than thepiezoelectric elements 62 and 64. According to this arrangement, it ispossible to allow the oscillator 6 to oscillate at high efficiency.

[0169] The reinforcing plate 63 is also furnished with a function as acommon electrode for the piezoelectric elements 62 and 64. To be morespecific, an alternating current voltage is applied to the piezoelectricelement 62 by the electrode 61 and the reinforcing plate 63, and analternating current voltage is applied to the piezoelectric element 64by the electrode 65 and the reinforcing plate 63.

[0170] The piezoelectric elements 62 and 64 repetitively expand andcontract in the length direction when an alternating current voltage isapplied, and in association with such expansion and contraction, thereinforcing plate 63 repetitively expands and contracts in the lengthdirection. In other words, when an alternating current voltage isapplied to the piezoelectric elements 62 and 64, the oscillator 6oscillates in the length direction at a minute amplitude, that is, itoscillates longitudinally, as indicated by an arrow of FIG. 3.

[0171] A convex portion 66 (e.g., a projection in the form of a tab) isformed integrally with the reinforcing plate 63 at the right end portionof FIG. 3. As shown in FIGS. 1 and 2, the oscillator 6 is located sothat the convex portion 66 touches the ring 53 of the rotor 5.

[0172] The convex portion 66 is provided at a position shifted from acenter line 69 at the center of the reinforcing plate 63 in the widthdirection, and is positioned at one corner portion according to thearrangement shown in the drawing. Also, according to the arrangementshown in the drawing, a similar convex portion 67 is providedsymmetrically with the convex portion 66 in the corner portion at theopposite angle on the diagonal line. The convex portion 67 is not usedaccording to the arrangement shown in FIG. 3.

[0173] Also, an arm portion 68 is provided so as to protrude in adirection nearly perpendicular to the length direction essentially fromthe center of the reinforcing plate 63. The arm portion 68 is providedwith a hole 681 at its tip end portion, into which a bolt 13 (see FIGS.1 and 2) is inserted.

[0174] As shown in FIGS. 1 and 2, the oscillator 6 arranged as above islocated so as to touch the ring 53 of the rotor 5 from the outercircumference side in the radius direction.

[0175] Also, the oscillator 6 is located in an orientation substantiallyin parallel with the rotor 5. This arrangement is advantageousparticularly in reducing the thickness of the entire tube pump 1A.

[0176] In addition, in the present embodiment, the thickness of theoscillator 6 is less than the thickness of the rotor 5, and the entireoscillator 6 is positioned within a space as thick as the rotor 5 in thevertical direction. This arrangement is advantageous particularly inreducing the thickness of the entire tube pump 1A.

[0177] The oscillator 6 is secured to a screw hole 239 made in the base21 with the bolt 13 in close proximity to the hole 681 of the armportion 68. In short, the oscillator 6 is supported by the arm portion68. This arrangement allows the oscillator 6 to oscillate freely and tooscillate at a relatively large amplitude. Also, the oscillator 6 islocated in a state that the convex portion 66 is pressure-contacted tothe inner face 532 of the ring 53 due to the elasticity of the armportion 68.

[0178] By allowing the oscillator 6 to oscillate by applying analternating current voltage to the piezoelectric elements 62 and 64 inthe state that the convex portion 66 touches the ring 53, the ring 53receives a frictional force and a pressing force from the convex portion66 when the oscillator 6 expands, and the rotor 5 rotates in a clockwisedirection of FIG. 1 as it repetitively receives the frictional force andthe pressing force.

[0179] As has been described above, in the present embodiment, the ring53 serving as the driven member is fixed to the rotor main body 51 bypress-fit, for example, so that the rotor 5 is rotationally drivendirectly by the oscillator 6. Consequently, the rotor 5 serves as both arotor for the tube pump 1A and a rotor for an ultrasonic wave motor,which makes the tube pump 1A advantageous particularly in reducing thesize and the thickness. Also, because the structure can be extremelysimple, it is possible to save manufacturing costs.

[0180] Incidentally, the ring 53 may be formed integrally with the rotormain body 51 from a single member.

[0181] Also, in the present embodiment, because in-plane oscillations ofthe oscillator 6 are directly converted into rotations of the rotor 5,energy loss incident to this conversion is so small that it is possibleto rotationally drive the rotor 5 at high efficiency.

[0182] Also, in the present embodiment, the direction of the frictionalforce and the pressing force conferred to the ring 53 from the convexportion 66 is nearly perpendicular to the rotor rotational axis 52,which prevents the rotor 5 from tilting, thereby allowing the rotor 5 torotate more smoothly in a reliable manner.

[0183] In addition, different from the case of a typical motor using amagnetic force for driving, the oscillator 6 drives the ring 53 with theaforementioned frictional force and the pressing force, thereby yieldinga high driving force. Hence, it is possible to rotate the rotor 5 withsufficient torque without disposing a speed reducing mechanism asdescribed in the present embodiment.

[0184] The frequency of an alternating current voltage applied to thepiezoelectric elements 62 and 64 is not especially limited, butpreferably, it is nearly as high as the resonance frequency of thelongitudinal oscillations of the oscillator 6. According to thisarrangement, the amplitude of the oscillator 6 becomes larger, whichmakes it possible to rotationally drive the rotor 5 at a higherefficiency.

[0185] As has been described above, the oscillator 6 chiefly oscillateslongitudinally in the length direction; however, it is more preferableto allow the convex portion 66 to oscillate elliptically by resonatinglongitudinal oscillations and flex oscillations. This arrangement makesit possible to rotationally drive the rotor 5 at higher efficiency. Thefollowing description will describe this point.

[0186] As shown in FIG. 4, when the oscillator 6 rotationally drives therotor 5, the convex portion 66 receives a reactive force from the rotor5 as indicated by an arrow of FIG. 4. In the present embodiment, becausethe convex portion 66 is provided at a position shifted from the centerline 69 of the oscillator 6, when the oscillator 6 oscillates, it isdeformed by the reactive force to bend in the in-plane direction asshown in FIG. 4. Deformation of the oscillator 6 is emphasized in theillustration of FIG. 4.

[0187] By selecting the frequency of an applied voltage, the shape andsize of the oscillator 6, and the position of the convex portion 66 asneeded, it is possible to set the frequency of the flex oscillationsnearly as high as the frequency of the longitudinal oscillations. Whenarranged in this manner, the longitudinal oscillations and the flexoscillations of the oscillator 6 resonate, which not only makes theamplitude larger, but also allows the convex portion 66 to be displacedalong an ellipse indicated by an alternate long and short dash line ofFIG. 5. In short, the convex portion 66 moves elliptically.

[0188] As a result, during one cycle of the amplitude of the oscillator6, the convex portion 66 is pressure-contacted to the ring 53 with astrong force when the convex portion 66 sends the ring 53 in therotational direction, and when the convex portion 66 returns, thefrictional force caused with the ring 53 is reduced or eliminated.Hence, the oscillations of the oscillator 6 can be converted intorotations of the rotor 5 at higher efficiency.

[0189] In the present invention, besides the advantage of being able toreduce the size and the thickness, there is another advantage that theperipheral equipment remains unaffected, because a typical motor is notused to rotate the rotor 5 and electromagnetic noises caused by thetypical motor are none at all or minimal, if any.

[0190] Also, when the rotor 5 is not driven rotationally, that is, whenthe rotor 5 is at rest, the frictional force between the convex portion66 and the ring 53 prevents the rotor 5 from rotating. In other words,the retention torque of the rotor 5 when the rotor 5 is at rest is high.Consequently, the rotor 5 will not rotate accidentally in the reversedirection by a pressure of a fluid within the tube 100 or the like,thereby making it possible to prevent backflow of the fluid within thetube 100.

[0191] Also, in the present embodiment, as shown in FIG. 2, there is nocomponent that needs to be assembled from the lower side of the base 21at the time of fabrication, and the components are assembled in onedirection, that is, only from the upper side of FIG. 2, in fabricatingthe tube pump, which offers another advantage of making the fabricationeasier.

[0192] In the present embodiment, one oscillator 6 is provided; however,in the present invention, more than one oscillator 6 may be provided.

[0193] (Second Embodiment)

[0194]FIG. 6 is a cross-sectional side view showing a second embodimentof the tube pump of the present invention. In the following description,the upper side and the lower side of FIG. 6 are assumed to be “top” and“bottom”, respectively.

[0195] The following description will describe the second embodiment ofthe tube pump of the present invention with reference to this drawing;however, the following description will chiefly describe a differencefrom the first embodiment above and the description as to the similararrangements is omitted.

[0196] Compared with the tube pump 1A of the first embodiment above, ina tube pump 1B of the present embodiment, the rollers 10 are madesmaller in diameter and are moved to the inner circumference side of therotor 5.

[0197] Accordingly, the shape of the base 21 is changed by reducing theradius of curvature of the inner circumferential face 215. To be morespecific, a step 214 is formed in the wall portion 212, and a bottomportion 232 in the space 23 for accommodating the tube 100 and therollers 10 is made smaller in diameter than a top portion 231 of thespace 23 for accommodating the rotor 5.

[0198] The arc portion 103 of the tube 100 attached to the base 21arranged as above is positioned on the inside of the outermost radius ofthe rotor 5.

[0199] According to the above arrangement, in the present embodiment,the pressurizing portions like the rollers 10 are mounted at the innercircumference side of the rotor 5 as compared to the tube pump 1A of thefirst embodiment above, which makes it possible to reduce the torquerequired to rotate the rotor 5 in comparison with the tube pump 1A.Consequently, according to the tube pump 1B of the present embodiment,the size of the oscillator 6 can be reduced in comparison with the firstembodiment above, and hence, the size of the entire tube pump 1B can befurther reduced.

[0200] In the present embodiment, one oscillator 6 is provided; however,in the present invention, more than one oscillator 6 may be provided.

[0201] (Third Embodiment)

[0202]FIG. 7 is a plan view showing a third embodiment of the tube pumpof the present invention. FIG. 8 is a side view showing the tube pumpshown in FIG. 7. In the following description, the upper side and thelower side of FIG. 8 are assumed to be “top” and “bottom”, respectively.

[0203] The following description will describe the third embodiment ofthe tube pump of the present invention with reference to these drawings;however, the following description will chiefly describe a differencefrom the first embodiment above and the description as to the similararrangements is omitted.

[0204] In a tube pump 1C of the present embodiment, the oscillator 6 islocated so as to touch the rotor main body 51 of the rotor 5 along thedirection of the rotor rotational axis 52, and drives the rotor mainbody 51. In other words, in the present embodiment, the rotor main body51 is the driven member, and the ring 53 is omitted from the rotor 5.

[0205] The arm portion 68 of the oscillator 6 is fixed to the cover 22of the main body 2, and the convex portion 66 of the oscillator 6touches the vicinity of the outer circumference on the top face of therotor main body 51. Also, in the present embodiment, the convex portion66 is provided at almost the center of the oscillator 6 in the widthdirection.

[0206] The oscillator 6, when viewed in a plane shown in FIG. 7, islocated so that the length direction thereof is substantially inparallel with a tangential line 514 of the rotor main body 51. Also, asshown in FIG. 8, the oscillator 6 is located so as to tilt (e.g., beangled) with respect to the rotor main body 51. According to thesearrangements, it is possible to convert oscillations of the oscillator 6into rotations of the rotor 5 at a high efficiency.

[0207] As has been described, in the present embodiment, the oscillator6 touches the rotor main body 51 of the rotor 5 along the direction ofthe rotor rotational axis 52, which makes it possible to superimpose theoscillator 6 and the rotor 5. This provides a further advantage inreducing the size of the entire tube pump 1C, particularly in reducingthe occupied area in FIG. 7.

[0208] In the present embodiment, one oscillator 6 is provided; however,in the present invention, more than one oscillator 6 may be provided.

[0209] (Fourth Embodiment)

[0210]FIG. 9 is a partially cutaway plan view showing a fourthembodiment of the tube pump of the present invention. FIG. 10 is across-sectional side view taken along the plane of the line Z-Z of FIG.9. In the following description, the upper side and the lower side ofFIG. 10 are assumed to be “top” and “bottom”, respectively.

[0211] The following description will describe the fourth embodiment ofthe tube pump of the present invention with reference to these drawings;however, the following description will chiefly describe a differencefrom the first embodiment above and the description as to the similararrangements is omitted.

[0212] A tube pump 1D shown in FIGS. 9 and 10 is provided with a mainbody 7 having an attachment portion 70 to which an elastic tube 100 isattached, a rotor 8 mounted rotatably with respect to the main body 7, aplurality of oscillators 6 mounted to the main body 7, and a pluralityof rollers 10 mounted to the rotor 8.

[0213] As shown in FIG. 10, the main body 7 includes a substrate 71, arotor rotational axis 72 installed so as to protrude upward from thecentral portion of the substrate 71, and a wall portion 73 erectedupward from the periphery of the substrate 71.

[0214] An inner circumferential face 74 of the wall portion 73 inapproximately the right half of FIG. 9 is formed arc-wise about therotor rotational axis 72. A space 75 defined essentially disc-wise bybeing surrounded with the substrate 71 and the wall portion 73accommodates the rotor 8 described below.

[0215] The wall portion 73 in the left side of FIG. 9 is provided withslots 76 and 77, each of which communicates with the outside of the mainbody 7 from the space 75. The slot 76 is positioned at the upper side ofFIG. 9 and the slot 77 is positioned at the lower side of FIG. 9. Also,the slots 76 and 77 are formed essentially in a dogleg shape (e.g.,angled) so that they become closer to each other toward the left side ofFIG. 9.

[0216] In the present embodiment, an inner circumferential face 78 ofthe wall portion 73 between the slot 76 and the slot 77 is also formedarc-wise. However, the inner circumferential face 78 does not have to beformed arc-wise, and for example, it may be formed linearly.

[0217] The tube 100 is attached to the main body 7 arranged as abovealong the slot 76, the inner circumferential face 74, and the slot 77essentially in the shape of a letter C. In other words, the tube 100includes an arc portion 103 placed along the inner circumferential face74, a downstream portion 102 extending to the outside of the main body 7from one end of the arc portion 103 via the slot 76, and an upstreamportion 101 extending to the outside of the main body 7 from the otherend of the arc portion 103 via the slot 77.

[0218] As has been described, the attachment portion 70 for the tube 100is composed of the vicinity of the inner circumferential face 74 and theslots 76 and 77.

[0219] The rotor 8 includes a rotor main body 81 and an annular ring 82.

[0220] As shown in FIG. 10, the rotor main body 81 includes a baseportion 811 shaped like a circular plate and having a hole 813 at thecentral portion, a bearing placement portion 812 protrudingcylindrically downward from the edge portion of the hole 813, and a ringplacement portion 814 protruding cylindrically (annularly) downward fromthe base portion 811 and concentrically with the bearing placementportion 812 at the outer circumference side thereof.

[0221] With the rotor main body 81 arranged as above, the rotorrotational axis 72 is inserted into the hole 813 on the inside of thebearing placement portion 812, so that the rotor main body 81 is mountedrotatably on the rotor rotational axis 72 of the main body 7 throughbearings 11 and 12 both placed on the inside of the bearing placementportion 812.

[0222] As has been described, in the present embodiment, the main body 7is not provided with any member equivalent to the aforementioned cover22 and supports the rotor 8 from one side, that is, from the lower sideof the drawing. In short, the main body 7 does not cover the rotor 8from the upper side. This arrangement makes the tube pump 1Dadvantageous particularly in reducing the thickness.

[0223] Two roller rotational axes 83 are installed so as to protrudedownward from the base portion 811 at the outer circumference side ofthe ring placement portion 812. In short, the roller rotational axes 83are installed in parallel with the rotor rotational axis 72. The rollers10 are mounted on the respective roller rotational axes 83 throughunillustrated bearings. The two rollers 10 are mounted along thecircumferential direction of the rotor 8 at equiangular intervals, thatis, at intervals of 180°.

[0224] When the rotor 8 rotates in a counterclockwise direction of FIG.9, one or two rollers 10 squeeze the arc portion 103 of the tube 100along the rotational direction of the rotor 8 while pressurizing the arcportion 103 with the inner circumferential face 74, whereby a fluidwithin the tube 100 is fed forward. Consequently, the fluid is taken infrom the upstream portion 101 of the tube 100 and discharged from thedownstream portion 102 of the tube 100.

[0225] As shown in FIG. 10, in the present embodiment, essentially theentire rollers 10 are positioned in a space as thick as the rotor 8 inthe vertical direction. This arrangement makes the tube pump 1Dadvantageous particularly in reducing the thickness.

[0226] The ring 82 serving as a driven member is fixed to the innercircumference of the ring placement portion 812 by press-fit, forexample.

[0227] The oscillators 6 are mounted to the main body 7 at the innercircumference side of the ring 82. To be more specific, oscillator mountportions 79 each having a screw hole 791 are provided so as to protrudeupward from the substrate 71, so that the oscillators 6 are secured totheir respective oscillator mount portions 79 by the bolts 13 insertedinto the holes 681 of the arm portions 68.

[0228] The oscillators 6 are located so as to touch the ring 82 from theinner circumference side in the radius direction, and drive the ring 82of the rotor 8 to rotate in a counterclockwise direction of FIG. 9.

[0229] As has been described, in the present embodiment, the oscillators6 are positioned at the inner circumference side of the ring 82. Inother words, the entire oscillators 6 are positioned on the inside ofthe outermost radius of the rotor 8. This arrangement makes the tubepump ID further advantageous in reducing the size, particularly inreducing the occupied area in FIG. 9.

[0230] Also, a slot 821 is formed at the inner circumference of the ring82 along the circumferential direction, and the convex portions 66 ofthe oscillators 6 touch an inner face 822 of the slot 821. Thisarrangement makes it possible to achieve the same advantage attained inthe first embodiment above by providing the slot 531.

[0231] In the present embodiment, two oscillators 6 are provided, andthese two oscillators 6 together drive the rotor 8. This arrangementlessens a driving force that one oscillator 6 has to produce, andtherefore, makes it possible to reduce the size of each oscillator 6.Hence, they are suitable when mounted on the inside of the outermostradius of the rotor 8 as are in the present embodiment. Also, even whena plurality of the oscillators 6 are mounted at the outer circumferenceside of the rotor 8, the oscillators 6 contribute to a reduction of thesize of the tube pump ID, particularly a reduction of the occupied areain FIG. 9.

[0232] Also, the two oscillators 6 are mounted along the circumferentialdirection of the rotor 8 at nearly equiangular intervals, that is, atintervals of 180°. According to this arrangement, forces perpendicularto the axial direction that act on the bearings 11 an 12 are set off,thereby making it possible to reduce the loading on the bearings 11 and12.

[0233] In the present invention, three or more oscillators 6 may beprovided. In this case, it is preferable that the oscillators 6 aremounted along the circumferential direction of the rotor 8 at nearlyequiangular intervals.

[0234] (Fifth Embodiment)

[0235]FIG. 11 is a cross-sectional side view showing a fifth embodimentof the tube pump of the present invention. In the following description,the upper side and the lower side of FIG. 11 are assumed to be “top” and“bottom”, respectively.

[0236] The following description will describe the fifth embodiment ofthe tube pump of the present invention with reference to this drawing;however, the following description will chiefly describe a differencefrom the first embodiment above and the description as to the similararrangements is omitted.

[0237] A tube pump 1E of the present embodiment is provided with a mainbody 9 having a tube attachment slot 93 serving as an attachment portionto which an elastic tube 100 is attached, a rotor 5 mounted rotatablywith respect to the main body 9, an oscillator 6 mounted to the mainbody 9 so as to touch the rotor 5 from the outer circumference side, andballs 14 serving as a plurality of pressurizing portions provided to therotor 5.The main body 9 includes a substrate 91 and a rotor rotationalaxis 92 installed so as to protrude upward from the central portion ofthe substrate 91. The rotor 5 includes a rotor main body 51 and a ring53 fixed to the outer circumferential portion of the rotor main body 51by press-fit, for example.

[0238] As with the fourth embodiment above, the main body 9 supports therotor 5 from one side, which makes the tube pump 1E advantageousparticularly in reducing the thickness.

[0239] The substrate 91 is provided with the tube attachment slot 93 onthe top face along the circumferential direction of the rotor 5 at theinner circumference side of the outermost radius of the rotor 5. Inother words, the tube attachment slot 93 is provided so as to form anarc when viewed in an unillustrated plane. A segment of the tube 100 isattached so that it is inserted into the tube attachment slot 93, andthe segment positioned within the tube attachment slot 93 forms the arcportion 103.

[0240] The rotor main body 51 is provided with the balls 14 forpressurizing the arc portion 103 of the tube 100 from the upper side.Each ball 14 is provided so that the upper side thereof is fit into aconcave portion 511 formed at the bottom face of the rotor main body 51,and is allowed to rotate in an arbitrary direction with respect to therotor main body 51.

[0241] In the present embodiment, because the contact area between theballs 14 and the tube 100 is smaller than the case using the rollers 10,the rotational resistance of the balls 14 is small, which makes itpossible to reduce the torque required to drive the rotor 5. Also,because the pressurizing portions are composed of the balls 14, they arenot retained in any particular direction, and therefore, only the balls14 have to be accommodated or fit into the concave portions 511, whichobviates the roller rotational axes, thereby making it possible to makethe structure further simplified and smaller.

[0242] Further, as with the second embodiment above, because the arcportion 103 of the tube 100 is positioned on the inside of the outermostradius of the rotor 5, the torque required to rotate the rotor 5 isrelatively small. Hence, in the present embodiment, the oscillator 6 canbe further reduced in size, which makes it possible to further reducethe size of the entire tube pump 1E.

[0243] Also, in the present embodiment, by pressurizing the tube 100along the direction of the rotor rotational axis 92, the tube 100 andthe rotor 5 can be superimposed in the thickness direction of the rotor5, that is, in the direction of the rotor rotational axis 92. Thisarrangement is advantageous particularly in reducing the size of theentire tube pump 1E.

[0244] According to the arrangement shown in the drawing, the tubeattachment slot 93 is shaped to have a flat bottom. However, in a casewhere the balls 14 directly press the tube 100 like in the presentembodiment, it is more preferable that the tube attachment slot 93 hasan arc-like or semi-circular cross section, that is, a curved bottom.According to this arrangement, the tube 100 is pressurized at a portionthereof to be sealed in a shape such that its cross section forms acurved arc along a clearance between the balls 14 and the tubeattachment slot 93, thereby making it possible to pressurize the tube100 at a portion thereof to be sealed in a more reliable manner withouthaving any clearance.

[0245] In the present embodiment, one oscillator 6 is provided; however,in the present invention, more than one oscillator 6 may be provided.

[0246] (Sixth Embodiment)

[0247]FIG. 12 is a cross-sectional side view showing a sixth embodimentof the tube pump of the present invention. In the following description,the upper side and the lower side of FIG. 12 are assumed to be “top” and“bottom”, respectively.

[0248] The following description will describe the sixth embodiment ofthe tube pump of the present invention with reference to this drawing;however, the following description will chiefly describe a differencefrom the first embodiment above and the description as to the similararrangements is omitted.

[0249] With a tube pump 1F of the present embodiment, a tube attachmentslot 219 substantially similar to the aforementioned tube attachmentslot 93 serving as the attachment portion is provided on the top face ofthe bottom plate 211 of the base 21, and a segment of the tube 100 isattached so that it is inserted into the tube attachment slot 219. Thesegment positioned within the tube attachment slot 219 forms the arcportion 103.

[0250] The rotor main body 51 is provided with a plurality of convexportions 512 as the pressurizing portions at the bottom face thereof,and these convex portions 512 pressurize the arc portion 103 of the tube100 at a portion thereof to be sealed from the upper side.

[0251] Like these convex portions 512, in the present invention, thepressurizing portions may be provided immovably to the rotor 5. Thisarrangement can make the structure of the pressurizing portions furthersimplified. In this case, it is preferable to reduce friction betweenthe tube 100 and the pressurizing portions like the convex portions 512by coating both or one of the outer surface of the tube 100 and thesurface of the pressurizing portions like the convex portions 512 with alow friction material or by applying a lubricant. Examples of the lowfriction material include fluorine-based resin, such aspolytetrafluoro-ethylene (Teflon).

[0252] Also, as with the fifth embodiment above, in the presentembodiment, by pressurizing the tube 100 along the direction of therotor rotational axis 52, the tube 100 and the rotor 5 can besuperimposed in the thickness direction of the rotor 5, that is, in thedirection of the rotor rotational axis 52, which is advantageousparticularly in reducing the size of the entire tube pump 1F.

[0253] In the present embodiment, one oscillator 6 is provided; however,in the present invention, more than one oscillator 6 may be provided.

[0254] (Seventh Embodiment)

[0255]FIG. 13 is a cross-sectional side view showing a seventhembodiment of the tube pump of the present invention. In the followingdescription, the upper side and the lower side of FIG. 13 are assumed tobe “top” and “bottom”, respectively.

[0256] The following description will describe the seventh embodiment ofthe tube pump of the present invention with reference to this drawing;however, the following description will chiefly describe a differencefrom the first embodiment above and the description as to the similararrangements is omitted.

[0257] A tube pump 1G of the present embodiment is provided with a mainbody 97 having a tube attachment slot 972 serving as an attachmentportion to which an elastic tube 100 is attached, a gear rotor 98serving as a rotor mounted rotatably with respect to the main body 97,rollers 99 serving as a plurality of pressurizing portions provided tothe gear rotor 98, an oscillator 6 mounted to the main body 97, a drivenmember 18 driven by the oscillator 6, and a rotational forcetransmission mechanism 19.

[0258] The main body 97 as a whole is essentially shaped like a plate,and includes a rotor rotational axis 971 installed so as to protrudeupward.

[0259] The gear rotor 98 includes a base portion 981 essentially shapedlike a circular plate, and a bearing placement portion 983 protrudingcylindrically downward from the edge portion of a hole 982 made in thebase portion 981 at the central portion thereof. Teeth of a gear areformed at the outer circumference of the base portion 981, and the gearrotor 98 serves also as a gear.

[0260] With the gear rotor 98 arranged as above, the rotor rotationalaxis 971 is inserted into the hole 982 on the inside of the bearingplacement portion 983, so that the gear rotor 98 is mounted rotatably onthe rotor rotational axis 971 of the main body 97 through bearings 11and 12 both placed on the inside of the bearing placement portion 983.

[0261] As has been described, in the present embodiment, the main body97 supports the gear rotor 98 from one side, that is, from the lowerside. This arrangement, as with the fourth embodiment above, makes thetube pump 1G advantageous particularly in reducing the thickness.

[0262] In the present embodiment, the driven member 18 driven by theoscillator 6 and the gear rotor 98 are provided separately, and thedriven member 18 rotates the gear rotor 98 through the rotational forcetransmission mechanism 19.

[0263] The driven member 18 is essentially shaped like a disc, andmounted rotatably on a driven member rotational axis 973 provided to themain body 97 through an unillustrated bearing. A slot 181 similar to theaforementioned slot 531 is formed at the outer circumference of thedriven member 18.

[0264] The main body 97 is provided with the oscillator 6 in such amanner that the convex portion 66 thereof touches the inner face of theslot 181. According to this arrangement, like the aforementioned rotor5, the driven member 18 is driven rotationally by the oscillator 6.

[0265] The rotational force transmission mechanism 19 is composed of aspur gear train, which includes a pinion 191, a gear wheel 192 thatengages with the pinion 191, and a pinion 193 coaxially fixed to thegear wheel 192.

[0266] The pinion 191 is coaxially fixed to the driven member 18 androtates together with the driven member 18.

[0267] The gear wheel 192 and the pinion 193 are mounted rotatably on agear rotational axis 974 provided to the main body 97 throughunillustrated bearings and rotate together. The pinion 193 is mounted soas to engage with the gear rotor 98.

[0268] The rotational force transmission mechanism 19 arranged as abovereduces the speed of rotation of the driven member 18 in two steps andtransmits the same to the gear rotor 98. In short, the rotational forcetransmission mechanism 19 serves as a speed changing unit, inparticular, a speed reducing unit.

[0269] Also, according to the arrangement shown in the drawing, thedriven member 18 and the gear rotor 98 rotate in the same direction. Itshould be appreciated, however, that by selecting the number of gears,etc., the driven member 18 and the gear rotor 98 rotate in the oppositedirections.

[0270] In the present embodiment, by driving the gear rotor 98 throughthe rotational force transmission mechanism 19, it is possible toheighten a degree of freedom as to where the oscillator 6 is located.Also, by changing the rotational speed with the rotational forcetransmission mechanism 19, the gear rotor 98 is allowed to rotate at adesired speed, which makes it possible to adjust a fluid feeding speed.In particular, in a case where the rotational speed is reduced by therotational force transmission mechanism 19, a small driving force fromthe oscillator 6 is sufficient, thereby making it possible to furtherreduce the oscillator 6 in size.

[0271] The rotational force transmission mechanism 19 is not limited tothe gear train as shown in the drawing, and for example, it may be awinding transmission mechanism using a pulley, a belt, a chain, etc.Alternatively, it may be a unit such that changes directions ofrotational axes of the driven member 18 and the gear rotor 98 by using abevel gear, worm gears, etc.

[0272] The main body 97 is provided with the tube attachment slot 972 onthe top face along the circumferential direction of the gear rotor 98 atthe inner circumference side of the outermost radius of the gear rotor98. In short, the tube attachment slot 972 is provided so as to form anarc when viewed in an unillustrated plane. A segment of the tube 100 isattached so that it is inserted into the tube attachment slot 972, andthe segment positioned within the tube attachment slot 972 forms the arcportion 103.

[0273] The base portion 981 of the gear rotor 98 is provided withrollers 99 that pressurize the arc portion 103 of the tube 100 at theportion thereof to be sealed from the upper side. Each roller 99includes a rotational axis 991, and the rotational axis 991 is installedso as to intersect with the rotor rotational axis 971 at nearly rightangles.

[0274] The base portion 981 is provided with windows 984 serving asholes into which the upper portions of the rollers 99 are inserted.Also, the base portion 981 is provided with rotational axis insert slots985 at the bottom face in close proximity to the windows 984, so that byinserting the rotational axes 991 into the rotational axis insert slots985, the gear rotor 98 supports the rollers 99 rotatably. Because thetube 100 or a touching portion 975 described below constantly touchesthe lower sides of the rollers 99, the rotational axes 991 will not comeoff from the rotational axis insert slots 985.

[0275] In the present embodiment, because the arc portion 103 of thetube 100 is positioned on the inside of the outermost radius of the gearrotor 98, as with the second embodiment above, there is offered anadvantage that the torque required to rotate the gear rotor 98 isrelatively small. Hence, according to the present embodiment, theoscillator 6 can be further reduced in size, which makes it possible tofurther reduce the size of the entire tube pump 1G.

[0276] Also, in the present embodiment, as with the fifth embodimentabove, by pressurizing the tube 100 along the direction of the rotorrotational axis 971, the tube 100 and the gear rotor 98 can besuperimposed in the thickness direction of the gear rotor 98, that is,in the direction of the rotor rotational axis 971. This arrangement isadvantageous particularly in reducing the size of the entire tube pump1G.

[0277] The main body 97 includes the touching portion 975 that touchesthe roller 99, like the roller 99 in the right side of FIG. 13, which ispresent at a position for not pressurizing the arc portion 103 of thetube 100. By providing the touching portion 975, there can be offered anadvantage as follows.

[0278] The gear rotor 98 receives a force that tilts the gear rotor 98due to a reactive force from the arc portion 103 of the tube 100 thatthe rollers 99 pressurize at a portion thereof to be sealed. In otherwords, this force functions so that the gear rotor 98 tilts downward tothe right of FIG. 13. At this point, in the present embodiment, byallowing the roller 99 in the right side of FIG. 13 to touch thetouching portion 975, the gear rotor 98 is prevented from tilting,thereby allowing the gear rotor 98 to rotate more smoothly in a reliablemanner. Also, the arc portion 103 of the tube 100 can be pressurized ata portion thereof to be sealed in a reliable manner without the roller99 in the left side of FIG. 13 being lifted up.

[0279] In the present embodiment, one oscillator 6 is provided; however,in the present invention, more than one oscillator 6 may be provided.

[0280] (Eighth Embodiment)

[0281]FIG. 14 is a partially cutaway plan view showing an eighthembodiment of the tube pump of the present invention. FIG. 15 is across-sectional side view taken along the plane of the line U-U of FIG.14. In the following description, the upper side and the lower side ofFIG. 15 are assumed to be “top” and “bottom”, respectively.

[0282] The following description will describe the eighth embodiment ofthe tube pump of the present invention with reference to these drawings;however, the following description will chiefly describe a differencefrom the embodiments described above and the description as to thesimilar arrangements is omitted.

[0283] The present embodiment is the same as the fourth embodiment aboveexcept that a thin plate 96 is provided in close proximity to the tube100 attached to the attachment portion 70.

[0284] With a tube pump 1H of the present embodiment, the thin plate 96as a flexible plate member is provided along the inner circumference ofthe tube 100 attached to the attachment portion 70 essentially in theshape of a letter C, and the rollers 10 pressurize a segment of the archportion 103 of the tube 100 at a portion thereof to be sealed throughthe thin plate 96.

[0285] The thin plate 96 is shaped like a strip and is located so as totouch the inner circumference of the tube 100 attached to the attachmentportion 70. The thin plate 96 is displaceable in the thicknessdirection, and segments pressed by the rollers 10 are displaced towardthe outer circumference side.

[0286] Also, the thin plate 96 is secured to the main body 7 in closeproximity to the slot 76 at a securing portion 961 at one end, andsecured to the main body 7 in close proximity to the slot 77 at asecuring portion 962 at the other end. This arrangement prevents thethin plate 96 from moving in the in-plane direction, that is, in therotational direction of the rotor 8, as being secured to the securingportions 961 and 962.

[0287] In the present embodiment, by using the thin plate 96 arranged asabove, the tube 100 is prevented from being in direct friction with thepressurizing portions like the rollers 10, and the tube 100 onlyreceives a force in a flattened direction, that is, in a directionintersecting at right angles with the axial direction of the tube 100from the pressurizing portions like the rollers 10, and receives noforce that drags the tube 100, that is, a force in the axial directionof the tube 100. Hence, the tube 100 is prevented from moving ortwisting, which makes it possible to feed a fluid smoothly. Also,deterioration of the tube 100 is prevented, and the lifespan of the tube100 can be extended.

[0288] The securing portions 961 and 962 are preferably secured to themain body 7 by an unillustrated screw tightening mechanism or anunillustrated arbitrary sandwiching mechanism, such as a clip, so thatthe thin plate 96 is preferably detachable/attachable from/to the mainbody 7. By providing the thin plate 96 in a detachable/attachablemanner, it is possible to replace the thin plate 96. Hence, when thethin plate 96 is deteriorated or damaged, it can be replaced with a newone. Also, the thin plate 96 can be replaced with a thin plate 96 of thesame kind having different thickness, quality of materials, hardness,etc. in response to the fluid feeding speed, that is, a rotational speedof the rotor 8, the diameter of the rollers 10, and the diameter,quality of materials, and hardness of the tube 100, etc., which makes itpossible to selectively use an optimal thin plate 96 as needed.

[0289] In the present embodiment, the thin plate 96 is provided from thevicinity of the slot 76 to the vicinity of the slot 77, so that it isprovided across the arc portion 103, which is a segment of the tube 100pressurized at a portion thereof to be sealed by the rollers 10.According to this arrangement, the advantages described above can beattained across the segment. Therefore, as has been described, it ispreferable that the thin plate 96 is provided almost across the segmentof the tube 100 pressurized at a portion thereof to be sealed by therollers 10, namely, the arc portion 103.

[0290] A forming material of the thin plate 96 is not especiallylimited, but a low friction material is preferable, examples of whichinclude metal materials of various kinds, and synthetic resin materialsof various kinds, such as polytetrafluoro-ethylene (Teflon).

[0291] Also, the thin plate 96 preferably has the ability to restore tothe original shape after it is deformed, that is, elasticity.

[0292] In addition, the thickness of the thin plate 96 is not especiallylimited, but a preferable thickness is approximately 0.005 to 0.1 mm. Ifthe thin plate 96 is too thick, the thin plate 96 will not readilydeform depending on the forming material thereof, and the tube 100 maynot be pressurized at a portion thereof to be sealed in a satisfactorymanner. On the other hand, when the thin plate 96 is too thin, the thinplate 96 may readily break depending on the forming material thereof.

[0293] Also, according to the present embodiment, it is possible toreduce the size of the pressurizing portions like the rollers 10 byusing the thin plate 96.

[0294] When the pressurizing portions like the rollers 10 are reduced insize, the pressing area is diminished in general and they engage in thetube 100 when pressurizing the same, which may cause inconveniences by,for example, accelerating deterioration of the tube 100, interferingwith smooth rotations of the rotor 8, etc.

[0295] In contrast, in the present embodiment, an area pressing the tube100 is enlarged by pressurizing the tube 100 through the thin plate 96,so that the pressing force can be dispersed across the in-plane of thethin plate 96. To be more specific, even when the pressurizing portionslike the rollers 10 are made smaller in diameter, they pressurize thetube 100 at a portion thereof to be sealed with a large curvaturebecause of the rigidity of the thin plate 96, thereby making it possibleto prevent local deformation of the tube 100. Hence, no inconveniencesas described above will arise even when the pressurizing portions likethe rollers 10 are reduced in size or the pressurizing portions are theballs 14 having small pressure-contacted points. In view of theforegoing, in the present embodiment, the pressurizing portions like therollers 10 can be reduced in size, which makes it possible to furtherreduce the size of the entire tube pump 1H.

[0296] (Ninth Embodiment)

[0297]FIG. 16 is a plan view showing a ninth embodiment of the tube pumpof the present invention. FIG. 17 is a cross-sectional side view takenalong the plane of the line V-V of FIG. 16. In the followingdescription, the upper side and the lower side of FIG. 17 are assumed tobe “top” and “bottom”, respectively.

[0298] The following description will describe the ninth embodiment ofthe tube pump of the present invention with reference to these drawings;however, the following description will chiefly describe a differencefrom the embodiments described above and the description as to thesimilar arrangements is omitted.

[0299] The present embodiment is the same as the fifth embodiment aboveexcept that a thin plate 16 is provided.

[0300] A tube pump 1J of the present embodiment is provided with a mainbody 9 having a tube attachment slot 93 serving as an attachment portionto which an elastic tube 100 is attached, a rotor 5 mounted rotatablywith respect to the main body 9, an oscillator 6 mounted to the mainbody 9 so as to touch the rotor 5 from the outer circumference side inthe radius direction, balls 14 serving as a plurality of pressurizingportions provided to the rotor 5, and the thin plate 16 disposed betweenthe rotor 5 and the tube 100.

[0301] As shown in FIG. 17, the main body 9 includes a substrate 91 anda rotor rotational axis 92 installed so as to protrude upward from thecentral portion of the substrate 91.

[0302] The substrate 91 is provided with, on the top face thereof, athin plate insert slot 94 of an annular shape about the rotor rotationalaxis 92.

[0303] The substrate 91 is further provided with, on the top facethereof, the tube attachment slot 93 essentially in the shape of aletter U when viewed in a plane shown in FIG. 16.

[0304] The tube attachment slot 93 is composed of an arc portion 931formed arc-wise about the rotor rotational axis 92, a linear portion 932extending downward in FIG. 16 from the left end portion of the arcportion 931 of FIG. 16, and a linear portion 933 extending downward inFIG. 16 from the right end portion of the arc portion 931 of FIG. 16.

[0305] As shown in FIG. 17, the arc portion 931 is formed at a bottomportion 941 of the thin plate insert slot 94. To be more specific, thewidth of the tube attachment slot 93 is less than the width of the thinplate insert slot 94, and the arc portion 931 is provided so as tofurther form a concave portion at the bottom portion 941 of the thinplate insert slot 94.

[0306] The tube 100 is attached to the main body 9 along the tubeattachment slot 93 arranged as above essentially in the shape of aletter U, and includes an arc portion 103 positioned at the arc portion931, an upstream portion 101 positioned at the linear portion 932, and adownstream portion 102 positioned at the linear portion 933.

[0307] The rotor main body 51 is provided with the two balls 14 servingas the pressurizing portions placed along the circumferential directionof the rotor 5 at nearly equiangular intervals, that is, at intervals of180°. Each ball 14 is provided so that the upper side thereof is fitinto a concave portion 511 formed at the bottom face of the rotor mainbody 51, and is allowed to rotate in an arbitrary direction with respectto the rotor main body 51.

[0308] These balls 14 pressurize a segment of the arc portion 103 of thetube 100 at a portion thereof to be sealed from the upper side throughthe thin plate 16 described below.

[0309] One oscillator 6 is provided at the outer circumference side ofthe rotor 5. As shown in FIG. 17, an oscillator mount portion 95 havinga screw hole 951 is provided so as to protrude from the substrate 91 atthe outer circumference side of the rotor 5, so that the oscillator 6 issecured to the oscillator mount portion 95 by the bolt 13 inserted intothe hole 681 in the arm portion 68. The oscillator 6 drives the rotor 5to rotate in a clockwise direction of FIG. 16.

[0310] The thin plate 16 is disposed between the tube 100 and the rotor5, so that the tube 100 is pressurized at a portion thereof to be sealedby the balls 14 through the thin plate 16.

[0311] The thin plate 16 is composed of an annular ring portion 161about the rotor rotational axis 92, and a securing portion 162 formed soas to protrude toward the outer circumference side from the ring portion161. The thin plate 16 is secured to the securing portion 162 by twobolts 17 in a detachable/attachable manner with respect to the main body9, and is arranged so as not to move in the in-plane direction of FIG.16.

[0312] The ring portion 161 is provided along the thin plate insert slot94 and covers the arc portion 103 of the tube 100 from the upper side.The width of the ring portion 161 is slightly less than the width of thethin plate insert slot 94.

[0313] As is shown at the right side of FIG. 17, a segment of the ringportion 161 pressed by the ball 14 is inserted into the thin plateinsert slot 94 as being displaced in the thickness direction thereof,that is, downward, whereby the tube 100 is pressurized at a portionthereof to be sealed.

[0314] At this point, the edge portion of the ring portion 161 touchesthe bottom portion 941 of the thin plate insert slot 94, so that anyfurther downward displacement is inhibited. According to thisarrangement, a position of the segment of the ring portion 161 pressedby the ball 14 and displaced in the thickness direction is determined,which not only prevents the ring portion 161 from tilting, but alsomakes it possible to pressurize the tube 100 at a portion thereof to besealed with a constant quantity of flattening all the time. Hence, it ispossible to prevent the tube 100 from being pressurized excessively at aportion thereof to be sealed, which suppresses deterioration of the tube100, thereby further extending the lifespan thereof.

[0315] As has been described, in the present embodiment, the bottomportion 941 functions as displacement quantity regulating means forregulating the thin plate 16 so as not to be displaced over a certainlimit. Herein, the shape and depth of the arc portion 931 of the tubeattachment slot 93 are set to attain an optimal quantity of flatteningof the tube 100.

[0316] In the present embodiment, one oscillator 6 is provided; however,in the present invention, more than one oscillator 6 may be provided.

[0317] (Tenth Embodiment)

[0318]FIG. 18 is a cross-sectional side view showing a tenth embodimentof the tube pump of the present invention. In the following description,the upper side and the lower side of FIG. 18 are assumed to be “top” and“bottom”, respectively.

[0319] The following description will describe the tenth embodiment ofthe tube pump of the present invention with reference to this drawing;however, the following description will chiefly describe a differencefrom the embodiments described above and the description as to thesimilar arrangements is omitted.

[0320] The present embodiment is the same as the sixth embodiment aboveexcept that the thin plate 16 is provided.

[0321] The main body 2 is provided with, on the top face of the bottomplate 211 of the base 21, a thin plate insert slot 237 substantiallysimilar to the aforementioned thin plate insert slot 94, and a tubeattachment slot 219 substantially similar to the aforementioned tubeattachment slot 93. The tube 100 is attached along the tube attachmentslot 219.

[0322] The rotor main body 51 is provided with a plurality of convexportions 512 serving as the pressurizing portions at the bottom facethereof, and these convex portions 512 pressurize the arc portion 103 ofthe tube 100 at a portion thereof to be sealed from the upper sidethrough the thin plate 16. In short, the convex portions 512 slide onthe thin plate 16.

[0323] In the present embodiment, because the pressurizing portionspressurize the tube 100 at a portion thereof to be sealed through thethin plate 16, the pressurizing portions do not contact the tube 100directly. Hence, even when the pressurizing portions are providedimmovably to the rotor 5 like the convex portions 512, it is possible toprevent deterioration of or damages on the tube 100 in a more reliablemanner, thereby extending the lifespan thereof.

[0324] In the present embodiment, it is preferable to reduce frictionbetween the thin plate 16 and the convex portions 512 by forming atleast the surfaces of both or one of the thin plate 16 and the convexportions 512 from a material having a relatively small coefficient offriction. Examples of the low friction material include fluorine-basedresin, such as polytetrafluoro-ethylene (Teflon).

[0325] Also, friction between the thin plate 16 and the convex portions512 may be reduced by applying a lubricant. Examples of the lubricantinclude grease, silicon oil, etc.

[0326] Segments of the thin plate 16 pressed by the convex portions 512are inserted into the thin plate insert slot 237, and the edge portionsthereof touch a bottom portion 238 of the thin plate insert slot 237. Asa result, as with the ninth embodiment above, it is possible topressurize the tube 100 at a portion thereof to be sealed at a constantquantity of flattening all the time.

[0327] In the present embodiment, one oscillator 6 is provided; however,in the present invention, more than one oscillator 6 may be provided.

[0328] (Eleventh Embodiment)

[0329]FIG. 19 is a plan view showing an eleventh embodiment of the tubepump of the present invention. FIG. 20 is a cross-sectional side viewtaken along the plane of the line W-W of FIG. 19. FIGS. 21 and 22 arecross-sectional plan views explaining a positional relation of ballswith respect to a rotor and a tube in the tube pump shown in FIGS. 19and 20. In the following description, the upper side and the lower sideof FIG. 20 are assumed to be “top” and “bottom”, respectively.

[0330] The following description will describe the eleventh embodimentof the tube pump of the present invention with reference to thesedrawings; however, the following description will chiefly describe adifference from the embodiments described above and the description asto the similar arrangements is omitted.

[0331] The present embodiment is the same as the ninth embodiment aboveexcept that a ball 15 serving as the pressurizing portion is allowed tomove with respect to a rotor 5 within a predetermined movable range.

[0332] A tube pump 1L of the present embodiment is provided with a mainbody 9 having a tube attachment slot 93 serving as an attachment portionto which an elastic tube 100 is attached, the rotor 5 mounted rotatablywith respect to the main body 9, an oscillator 6 mounted to the mainbody 9 for rotationally driving the rotor 5, balls 14 and 15 serving asthe pressurizing portions, and a thin plate 16 disposed between therotor 5 and the tube 100.

[0333] The rotor main body 51 of the rotor 5 is provided with the ball14 and the ball 15 both serving as the pressurizing portions forpressurizing the tube 100. Each of the balls 14 and 15 pressurizes asegment of the arc portion 103 of the tube 100 at a portion thereof tobe sealed from the upper side through the thin plate 16.

[0334] As shown in FIG. 20, the ball 14 is provided so that the upperside thereof is fit into a concave portion 513 formed at the bottom faceof the rotor main body 51, and the lower side of the ball 14 protrudesfrom the bottom face of the rotor main body 51. The distance between theconcave portion 513 and the rotor rotational axis 92 is substantiallyequal to the distance between the arc portion 103 and the rotorrotational axis 92.

[0335] The ball 14 is allowed to rotate on its axis in an arbitrarydirection with respect to the rotor 5. Also, the ball 14 is arranged soas not to move substantially with respect to the rotor 5. In otherwords, the concave portion 513 is of a size that does not allow the ball14 to move substantially with respect to the rotor 5.

[0336] On the other hand, the ball 15 is allowed to move with respect tothe rotor 5 within a range of a ball movement slot 55. In other words,the ball 15 is provided so that the upper side thereof is inserted intothe ball movement slot 55 formed at the bottom face of the rotor mainbody 51, so that it is allowed to move with respect to the rotor 5 alongthe ball movement slot 55.

[0337] Like the ball 14, the lower side of the ball 15 protrudes fromthe bottom face of the rotor main body 51. Also, like the ball 14, theball 15 is allowed to rotate on its axis in an arbitrary direction withrespect to the rotor 5.

[0338] As shown in FIG. 19, the ball movement slot 55 is formed arc-wisealong the circumferential direction of the rotor 5, and is provided alittle less than halfway from the vicinity of the ball 14 in the reversedirection of the normal rotational direction of the rotor 5, that is, ina counterclockwise direction of FIG. 19. The distance between the ballmovement slot 55 and the rotor rotational axis 92 is substantially equalto the distance between the arc portion 103 and the rotor rotationalaxis 92.

[0339] Hereinafter, the inner face of the end portion of the ballmovement slot 55 closer to the ball 14 is referred to as the front endface 551, and the inner face of the end portion farther from the ball 14is referred to as the rear end face 552.

[0340] According to these arrangements, the ball 15 is allowed to movewith respect to the rotor 5 between the position in close proximity tothe ball 14 and the front end face 551 (the state shown in FIG. 21), andthe position at the opposite side with respect to the ball 14 having therotor rotational axis 92 in between, that is, in close proximity to therear end face 552 (the states shown in FIGS. 19 and 22). In the statesshown in FIGS. 19 and 22, the balls 14 and 15 are positioned along thecircumferential direction of the rotor 5 at equiangular intervals, thatis, at intervals of 180°.

[0341] In the present embodiment, because the ball 15 is allowed to movewith respect to the rotor 5, as will be described below, it is possibleto prevent the tube 100 from having a flattening habit or to prevent thetube 100 from being blocked due to adhesion of the inner wall resultingfrom lamination thereof while the tube pump is not in use.

[0342] As shown in FIG. 21, with the tube pump 1L, by positioning theball 15 in close proximity to the ball 14 and by setting the rotationalposition of the rotor 5 so that both the balls 14 and 15 are positionedbetween the upstream portion 101 and the downstream portion 102 of thetube 100, there can be obtained a state that neither the ball 14 nor theball 15 is pressurizing the arc portion 103 of the tube 100.

[0343] Hence, by leaving the tube pump 1L in the state shown in FIG. 21while not in use, it is possible to prevent the tube 100 from having aflattening habit or being blocked due to adhesion of the inner wall.Thus, by leaving the tube pump 1L in the state shown in FIG. 21 at thetime of fabrication in the factory, for example, even when there is aconsiderable time until it is sold or used, the tube 100 will neitherhave a flattening habit nor be blocked due to adhesion of the innerwall.

[0344] When the rotor 5 starts to rotate in the state shown in FIG. 21,the ball 14 starts to revolve about the rotor rotational axis 92. On theother hand, the ball 15 remains at the same position with respect to themain body 9 and starts to move relatively with respect to the rotor 5along the ball movement slot 55.

[0345] When the state is changed as the rotor 5 rotates to the positionwhere the rear end face 552 touches the ball 15 (the state shown in FIG.22), the ball 15 is pressed by the rear end face 552 and starts torevolve about the rotor rotational axis 92.

[0346] In other words, when the rotor 5 starts to rotate in the stateshown in FIG. 21, the ball 15 moves with respect to the rotor 5 bystarting to revolve later than the ball 14, and automatically goes intothe state shown in FIG. 22.

[0347] Having shifted to the state shown in FIG. 22, that is, in thesteady rotation state of the rotor 5, the balls 14 and 15 revolve whilebeing placed along the circumferential direction of the rotor 5 atequiangular intervals, that is, at intervals of 180° (see FIG. 19).According to these arrangements, in the steady rotation state of therotor 5, at least one of the balls 14 and 15 pressurizes the arc portion103 of the tube 100 at a portion thereof to be sealed regardless of therotational position of the rotor 5. Hence, a fluid within the tube 100is fed smoothly in one direction without flowing backward.

[0348] As has been described, in the present embodiment, the ball 15automatically moves with respect to the rotor 5 when the rotor 5 startsto rotate. Hence, it is possible to prevent the tube 100 from having aflattening habit or being blocked due to adhesion of the inner wallwhile the tube pump is not in use without performing any specialmanipulation or the like, thereby achieving enhanced convenience. Also,by merely rotating the rotor 5 approximately halfway from a state whenthe tube pump is not in use shown in FIG. 21, the balls 14 and 15 can beplaced at the positions in the steady rotation state shown in FIG. 22.Hence, there is no delay in operation, that is, no delay in feeding thefluid.

[0349] When the operation of the tube pump 1L is stopped, the rotor 5can be stopped as it is returned to the state shown in FIG. 21 again bybeing rotated in the reverse direction, namely, in the counterclockwisedirection of FIGS. 21 and 22, by an adequate angle up to 360°. Byperforming this operation, it is possible to prevent the tube 100 fromhaving a flattening habit or being blocked due to adhesion of the innerwall not only in a period until the tube pump 1L is used first since theshipment from the factory, but also in an idle period between the useperiods of the tube pump 1L.

[0350] When the rotor 5 rotates more than once in the reverse direction,the balls 14 and 15 revolve at the positional relation shown in FIG. 21.Hence, when the rotor 5 rotates in the reverse direction, there is astate that neither the ball 14 nor the ball 15 is pressurizing the arcportion 103 of the tube 100 while the rotor 5 rotates once, during whichthe fluid flown backward within the tube 100 returns. Hence, the fluidwithin the tube 100 does not flow backward practically. As has beendescribed, in the present embodiment, there is another advantage thatthe fluid within the tube 100 does not flow backward practically evenwhen the rotor 5 rotates in the reverse direction because of sometrouble.

[0351] In the present embodiment, one oscillator 6 is provided; however,in the present invention, more than one oscillator 6 may be provided.

[0352] (Twelfth Embodiment)

[0353]FIG. 23 is a cross-sectional side view showing a twelfthembodiment of the tube pump of the present invention. FIGS. 24 and 25are cross-sectional plan views explaining a positional relation ofpressurizing portions with respect to a rotor and a tube in the tubepump shown in FIG. 23. In the following description, the upper side andthe lower side of FIG. 23 are assumed to be “top” and “bottom”,respectively.

[0354] The following description will describe the twelfth embodiment ofthe tube pump of the present invention with reference to these drawings;however, the following description will chiefly describe a differencefrom the embodiments described above and the description as to thesimilar arrangements is omitted.

[0355] A tube pump 1M of the present embodiment is the same as theeleventh embodiment above except that the arrangement and the number ofthe pressurizing portions are different.

[0356] In the present embodiment, three pressurizing portions 24, 25,and 26 protruding from the bottom face of the rotor main body 51 areprovided. These pressurizing portions 24, 25 and 26 are provided so thatthe distance from each to the rotor rotational axis 92 is substantiallyequal to the distance between the arc portion 103 of the tube 100 andthe rotor rotational axis 92, and each pressurizes a segment of the arcportion 103 at a portion thereof to be sealed from the upper sidethrough the thin plate 16. These pressurizing portions 24, 25, and 26 donot rotate on their respective axes and slide on the thin plate 16.

[0357] As shown in FIG. 23, the pressurizing portion 24 composed of aconvex portion is provided immovably to the rotor main body 51. In otherwords, the pressurizing portion 24 is fixed to the rotor main body 51and does not move with respect to the rotor 5. The pressurizing portion24 is formed so as to protrude almost cylindrically or disc-wise fromthe bottom face of the rotor main body 51.

[0358] On the other hand, the pressurizing portions 25 and 26 areallowed to move with respect to the rotor 5. In other words, the rotormain body 51 is provided with pressurizing portion movement slots 56 and57 at the bottom face thereof, and the pressurizing portions 25 and 26move along the pressurizing portion movement slots 56 and 57.

[0359] The pressurizing portion 25 is composed of a pressurizing portionmain body 251 and a cylindrical protrusion 252 protruding from the topface of the pressurizing portion main body 251. The pressurizing portionmain body 251 is a portion protruding from the bottom face of the rotormain body 51 and formed essentially cylindrically or disc-wise. Theprotrusion 252 fits into the pressurizing portion movement slot 56.

[0360] Likewise, the pressurizing portion 26 is composed of apressurizing portion main body 265 and a cylindrical protrusion 262protruding from the top face of the pressurizing portion main body 265.The major diameter of the protrusion 262 is less than that of theprotrusion 252, and the protrusion 262 fits into the pressurizingportion movement slot 56 or 57.

[0361] As shown in FIG. 24, the pressurizing portion movement slots 56and 57 are formed arc-wise along the circumferential direction of therotor 5.

[0362] The pressurizing portion movement slot 56 is provided in a littleless than 60° range of the central angle from the vicinity of thepressurizing portion 24 in the reverse direction of the normalrotational direction of the rotor 5, that is, in a counterclockwisedirection of FIG. 24. The width of the pressurizing portion movementslot 56 is substantially equal to or slightly larger than the majordiameter of the protrusion 252.

[0363] The pressurizing portion movement slot 57 is formed consecutivelyfrom the end portion of the pressurizing portion movement slot 56 in thesame direction, that is, in the counterclockwise direction of FIG. 24,and is provided in an approximately 60° range of the central angle. Thewidth of the pressurizing portion movement slot 57 is substantiallyequal to or slightly larger than the major diameter of the protrusion262. In short, the width of the pressurizing portion movement slot 57 isnarrower than the width of the pressurizing portion movement slot 56.

[0364] According to these arrangements, the pressurizing portion 26 isallowed to move along the pressurizing portion movement slots 56 and 57within the range of the pressurizing portion movement slots 56 and 57 asthe protrusion 262 thereof moves within the pressurizing portionmovement slots 56 and 57.

[0365] On the other hand, as to the pressurizing portion 25, because theprotrusion 252 thereof has the major diameter larger than the width ofthe pressurizing portion movement slot 57, it can move only up to aboundary portion 58 between the pressurizing portion movement slot 56and the pressurizing portion movement slot 57, and hence, is allowed tomove within the range of the pressurizing portion movement slot 56.

[0366] While the tube pump 1M is not in use, by bringing thepressurizing portions 25 and 26 into a state that they are moved inclose proximity to the pressurizing portion 24 as shown in FIG. 24,there can be obtained a state that none of the pressurizing portions 24,25, and 26 is pressurizing the arc portion 103 of the tube 100.Consequently, as with the eleventh embodiment above, it is possible toprevent the tube 100 from having a flattening habit or being blocked dueto adhesion of the inner wall while the tube pump is not in use.

[0367] When the rotor 5 starts to rotate in the state shown in FIG. 24,the pressurizing portion 24 starts to revolve about the rotor rotationalaxis 92. On the other hand, the pressurizing portions 25 and 26 remainat the same positions with respect to the main body 9 and moverelatively with respect to the rotor 5 along the pressurizing portionmovement slot 56.

[0368] When the rotor 5 rotates to a position where the wall face of theboundary portion 58 touches the pressurizing portion 25, thepressurizing portion 25 is pressed by the wall face of the boundaryportion 58 and starts to revolve about the rotor rotational axis 92. Thepressurizing portion 26 still remains at the same position and movesrelatively with respect to the rotor 5 along the pressurizing portionmovement slot 57.

[0369] When the rotor 5 rotates further to the position where a rear endface 571 of the pressurizing portion movement slot 57 touches thepressurizing portion 26, the pressurizing portion 26 is pressed by therear end face 571 and starts to revolve about the rotor rotational axis92. Consequently, as shown in FIG. 25, the pressurizing portions 24, 25,and 26 are in the state that they are placed along the circumferentialdirection of the rotor 5 at nearly equiangular intervals, that is, atintervals of 120°, namely, in the steady rotation state, and theysqueeze the tube 100 as they revolve in this state.

[0370] In the present embodiment, three pressurizing portions 24, 25,and 26 are provided, and the tube 100 is pressurized at more pointsthereof to be sealed, which makes it possible to feed a fluid moresmoothly, thereby making it possible to further reduce a change inpressure in the pump output.

[0371] Also, according to the arrangement shown in the drawing, the arcportion 103 of the tube 100 is formed in an approximately 180° range ofthe central angle. In the present embodiment, however, because thepressurizing portions 24, 25, and 26 are placed at intervals ofapproximately 120°, the range of the arc portion 103 of the tube 100 maybe shortened to an approximately 120° range of the central angle. Thisheightens a degree of freedom as to where the tube 100 is placed.

[0372] In the present invention, four or more pressurizing portions maybe provided. In this case, it is preferable that the pressurizingportions are placed along the circumferential direction of the rotor 5at nearly equiangular intervals.

[0373] Also, in the present embodiment, by providing the thin plate 16,it is possible to prevent deterioration of or damages on the tube 100even when the pressurizing portions are the ones that do not rotate ontheir axes like the pressurizing portions 24, 25, and 26.

[0374] Also, in the present embodiment, it is preferable to reducefriction between the thin plate 16 and the pressurizing portions 24, 25,and 26 by forming at least the surfaces of both or one of the thin plate16 and the pressurizing portions 24, 25, and 26 from a material having arelatively small coefficient of friction. Examples of the low frictionmaterial include fluorine-based resin, such as polytetrafluoro-ethylene(Teflon).

[0375] Also, friction between the thin plate 16 and the pressurizingportions 24, 25, and 26 may be reduced by applying a lubricant. Examplesof the lubricant include grease, silicon oil, etc.

[0376] In the present embodiment, one oscillator 6 is provided; however,in the present invention, more than one oscillator 6 may be provided.

[0377] (Thirteenth Embodiment)

[0378]FIG. 26 is a partially cutaway plan view showing a thirteenthembodiment of the tube pump of the present invention. FIG. 27 is across-sectional side view showing the vicinity of a rotor in the tubepump shown in FIG. 26. FIG. 28 is a cross-sectional developmentelevation showing a rotational force transmission mechanism in the tubepump shown in FIG. 26. FIGS. 29 and 30 are cross-sectional plan viewsexplaining a positional relation of rollers with respect to the rotorand a tube in the tube pump shown in FIG. 26. In the followingdescription, the upper side and the lower side of FIGS. 27 and 28 areassumed to be “top” and “bottom”, respectively.

[0379] The following description will describe the thirteenth embodimentof the tube pump of the present invention with reference to thesedrawings; however, the following description will chiefly describe adifference from the embodiments described above and the description asto the similar arrangements is omitted.

[0380] A tube pump 1N of the present embodiment is provided with a mainbody 3 having an attachment portion 30 to which an elastic tube 100 isattached, a gear rotor 4 serving as a rotor mounted rotatably withrespect to the main body 3, rollers 27 and 28 serving as pressurizingportions, an oscillator 6 mounted to the main body 3, a driven member 18driven by the oscillator 6, and a rotational force transmissionmechanism 19.

[0381] As shown in FIGS. 26 and 27, the main body 3 as a whole isessentially shaped like a plate, and a rotor rotational axis 31 isinstalled so as to protrude upward from the central portion thereof.

[0382] Also, the main body 3 is provided with a wall portion havinginner circumferential faces 32 and 33 formed arc-wise about the rotorrotational axis 31. The inner circumferential face 32 is formed alongapproximately halfway of the upper side of FIG. 26 and the innercircumferential face 33 is formed along approximately halfway of thelower side of FIG. 26.

[0383] Also, the main body 3 is provided with linear tube attachmentslots 34 and 35.

[0384] The tube 100 is attached to the main body 3 arranged as abovealong the tube attachment slot 34, the inner circumferential face 32,and the tube attachment slot 35 essentially in the shape of a letter U.To be more specific, the tube 100 includes an arc portion 103 placedarc-wise along the inner circumferential face 32, an upstream portion101 extending to the outside of the main body 3 from the left endportion of the arc portion 103 of FIG. 26 via the tube attachment slot34, and a downstream portion 102 extending to the outside of the mainbody 3 from the right end portion of the arc portion 103 of FIG. 26 viathe tube attachment slot 35.

[0385] As has been described, the attachment portion 30 for the tube 100is composed of the vicinity of the inner circumferential face 32 and thetube attachment slots 34 and 35.

[0386] As shown in FIG. 27, the gear rotor 4 includes a rotor main body41 essentially shaped like a circular plate, and a bearing placementportion 43 protruding cylindrically downward from the edge portion of ahole 42 made in the rotor main body 41 at the central portion thereof.Teeth of a gear are formed at the outer circumference of the rotor mainbody 41, and the gear rotor 4 serves also as a gear.

[0387] With the gear rotor 4 arranged as above, the rotor rotationalaxis 31 is inserted into the hole 42 on the inside of the bearingplacement portion 43, so that the gear rotor 4 is mounted rotatably onthe rotor rotational axis 31 of the main body 3 through bearings 11 and12 both placed on the inside of the bearing placement portion 43.Although it will be described below, the oscillator 6 drives the gearrotor 4 to rotate in a clockwise direction of FIG. 26.

[0388] As shown in FIG. 27, a pressure-applying rotor 29 is furthermounted rotatably on the rotor rotational axis 31. In short, thepressure-applying rotor 29 is provided coaxially with the gear rotor 4.The pressure-applying rotor 29 is essentially shaped like abottomed-cylinder, and is mounted in a state that the rotor rotationalaxis 31 is inserted into a hole 291 made at the center of the bottomportion thereof.

[0389] As to the fabrication order, the pressure-applying rotor 29 ismounted on the rotor rotational axis 31 first, and the gear rotor 4 ismounted thereon, so that the bearing placement portion 43 is positionedon the inside of the pressure-applying rotor 29. The pressure-applyingrotor 29 and the gear rotor 4 are allowed to rotate independently.

[0390] A roller rotational axis 44 is installed fixedly to the rotormain body 41 so as to protrude downward. In short, the roller rotationalaxis 44 is installed in parallel with the rotor rotational axis 31.

[0391] The roller 27 is mounted on the roller rotational axis 44 throughan unillustrated bearing so that it is allowed to rotate on its axis. Inshort, the roller 27 does not move with respect to the gear rotor 4.

[0392] The other roller 28 is a mere cylindrical member, and is notsupported by the gear rotor 4 with a rotational axis member like theroller rotational axis 44.

[0393] The rollers 27 and 28 are arranged so that they can be positionedat the inner circumference side of the arc portion 103 of the tube 100,and pressurize the arc portion 103 at a portion thereof to be sealedwith the inner circumferential face 32. In other words, the rollers 27and 28 pressurize the arc portion 103 at a portion thereof to be sealedfrom the inner circumference side in the radius direction of the gearrotor 4. According to these arrangements, in the present embodiment, thedirection of a reactive force that the gear rotor 4 receives from thearc portion 103 of the tube 100 becomes nearly perpendicular to therotor rotational axis 31, which prevents the gear rotor 4 from tilting,thereby allowing the gear rotor 4 to rotate more smoothly in a reliablemanner.

[0394] The inner circumferential face 33 is formed to have a radius ofcurvature so that it can touch the rollers 27 and 28 or leaves a minimalclearance with the rollers 27 and 28.

[0395] The rotor main body 41 is provided with a pressing roller 45serving as a pressing portion for pressing the roller 28 in therotational direction of the gear rotor 4. The pressing roller 45 ismounted on a pressing roller rotational axis 46, which is installedfixedly so as to protrude downward from the rotor main body 41, throughan unillustrated bearing so that it is allowed to rotate on its axis.The diameter of the pressing roller 45 is less than the diameters of therollers 27 and 28, and the pressing roller 45 is arranged so as not totouch the arc portion 103 and the inner circumferential face 33.

[0396] The roller 28 is inserted at a position so that it can touch thepressing roller 45 in the reverse direction of the rotational directionof the gear rotor 4, that is, in a counterclockwise direction of FIG.26.

[0397] According to these arrangements, the roller 28 is allowed to movewith respect to the gear rotor 4 between the position where it touchesthe pressing roller 45 (the states shown in FIGS. 26 and 30), and theposition where it touches the roller 27 (not shown). In the state thatthe roller 28 touches the pressing roller 45, the rollers 27 and 28 areplaced along the circumferential direction of the gear rotor 4 at nearlyequiangular intervals, that is, at intervals of 180°.

[0398] While the tube pump 1N is not in use, by bringing the rollers 27and 28 in the state that the latter is moved in close proximity to theformer as shown in FIG. 29, there can be obtained a state that neitherthe roller 27 nor the roller 28 is pressurizing the arc portion 103 ofthe tube 100. Consequently, as with the eleventh and twelfth embodimentsabove, it is possible to prevent the tube 100 from having a flatteninghabit or being blocked due to adhesion of the inner wall while the tubepump is not in use.

[0399] When the gear rotor 4 starts to rotate in the state shown in FIG.29, the roller 27 starts to revolve about the rotor rotational axis 31.On the other hand, the roller 28 remains at the same position withrespect to the main body 3, and moves relatively with respect to thegear rotor 4 in the circumferential direction.

[0400] When the state is changed as the gear rotor 4 rotates to theposition where the pressing roller 45 touches the roller 28 (the stateshown in FIG. 30), the roller 28 is pressed by the pressing roller 45 inthe rotational direction of the gear rotor 4, and starts to revolveabout the rotor rotational axis 31.

[0401] In the steady rotation state of the gear rotor 4 (the state afterthe state shown in FIG. 30), as shown in FIG. 26, the rollers 27 and 28keep revolving while being placed along the circumferential direction ofthe gear rotor 4 at nearly equiangular intervals.

[0402] When the roller 28 pressurizes the arc portion 103 of the tube100 at a portion thereof to be sealed, it receives a force directingtoward the outer circumference side in the radius direction of the gearrotor 4 from the pressure-applying rotor 29 and pressurizes the tube 100at a portion thereof to be sealed with that force.

[0403] Also, the roller 28 rotates about the rotational axis 281 as itsaxis while contacting the pressure-applying rotor 29 and the pressingroller 45. In other words, each of the rollers 27 and 28 and thepressure-applying rotor 29 rotates on their respective axes as indicatedby arrows of FIG. 26, and operate as a planetary gear mechanism as awhole. Consequently, the tube pump 1N of the present embodiment canachieve an extremely smooth operation.

[0404] As has been described, in the present embodiment, by providingthe pressure-applying rotor 29 and the pressing roller 45, it is nolonger necessary to support the roller 28, which is movable with respectto the gear rotor 4, by a rotational axis member.

[0405] Different from the above arrangement, in the case of supportingthe roller 28 by the rotational axis member, it is necessary to provide,for example, arm members at the top and bottom of the gear rotor 4 forsupporting the rotational axis member at the top and bottom thereof andfor allowing the roller 28 to move with respect to the gear rotor 4,which increases the dimension in the thickness direction, that is, inthe vertical direction of FIG. 27. In contrast, the present embodimentdoes not cause such an inconvenience, and therefore, the tube pump 1Ncan prevent the tube 100 from having a flattening habit, and at the sametime, is advantageous particularly in reducing the thickness.

[0406] Also, in the present embodiment, the driven member 18 driven bythe oscillator 6 and the gear rotor 4 are provided separately, and thedriven member 18 rotates the gear rotor 4 through the rotational forcetransmission mechanism 19. The rotational force transmission mechanism19 is composed of a spur gear train substantially similar to thecounterpart in the seventh embodiment.

[0407] As shown in FIGS. 26 and 28, the driven member 18 is mountedrotatably on a driven member rotational axis 36 provided to the mainbody 3 through an unillustrated bearing.

[0408] A gear wheel 192 and a pinion 193 are mounted rotatably on a gearrotational axis 37 provided to the main body 3 through unillustratedbearings, and rotate together. The pinion 193 is mounted so as to engagewith the gear rotor 4.

[0409] In the present embodiment, one oscillator 6 is provided; however,in the present invention, more than one oscillator 6 may be provided.

[0410] (Fourteenth Embodiment)

[0411]FIG. 31 is a plan view showing a fourteenth embodiment of the tubepump of the present invention. FIG. 32 is a cross-sectional side viewshowing the vicinity of a rotor in the tube pump shown in FIG. 31. FIG.33 is a cross section showing a mount portion of a movable roller in thetube pump shown in FIG. 31. In the following description, the upper sideand the lower side of FIG. 32 are assumed to be “top” and “bottom”,respectively.

[0412] The following description will describe the fourteenth embodimentof the tube pump of the present invention with reference to thesedrawings; however, the following description will chiefly describe adifference from the embodiments described above and the description asto the similar arrangements is omitted.

[0413] A tube pump 1P of the present embodiment is provided with a mainbody 86 having a tube attachment slot 863 serving as an attachmentportion to which an elastic tube 100 is attached, a gear rotor 4 servingas a rotor mounted rotatably with respect to the main body 86, rollers87 and 88 serving as pressurizing portions provided to the gear rotor 4,an oscillator 6 mounted to the main body 86, a driven member 18 drivenby the oscillator 6, and a rotational force transmission mechanism 19for transmitting rotations of the driven member 18 to the gear rotor 4with a reduced speed.

[0414] As shown in FIGS. 31 and 32, the main body 86 as a whole isessentially shaped like a plate, and a rotor rotational axis 861 isinstalled so as to protrude upward from the central portion thereof.

[0415] Also, the main body 86 is provided with, on the top face thereof,the tube attachment slot 863 essentially in the shape of a letter U whenviewed in a plane shown in FIG. 31. The tube 100 is attached to the mainbody 86 along the tube attachment slot 863 essentially in the shape of aletter U.

[0416] The rotor main body 41 of the gear rotor 4 is provided with therollers 87 and 88, each of which serves as the pressurizing portion andis allowed to rotate on its axis. The rollers 87 and 88 are respectivelyprovided with rotational axes 871 and 881 protruding from theirrespective rollers, and these rotational axes 871 and 881 are installedso as to intersect with the rotor rotational axis 861 at nearly rightangles. The rollers 87 and 88 pressurize the arc portion 103 of the tube100 at a portion thereof to be sealed from the upper side with a bottom864 of the tube attachment slot 863.

[0417] The roller 87 is mounted so as not to move with respect to thegear rotor 4. The roller 87 is mounted in a state that the upper sidethereof is inserted into a hole made in the rotor main body 41 as awindow 47.

[0418] The rotor main body 41 is provided with two rotational axisinsert slots 471 in close proximity to the window 47 at the bottom facethereof, and the roller 87 is supported rotatably by the gear rotor 4 asboth end portions of the rotational axis 871 are inserted into the tworotational axis insert slots 471, respectively.

[0419] The roller 88 is mounted movably with respect to the gear rotor4. The roller 88 is mounted in a state that the upper side thereof isinserted into a hole made in the rotor main body 41 as a window 48. Therotor main body 41 is provided with two rotational axis insert slots 481in close proximity to the window 48 at the bottom face thereof, and theroller 88 is supported rotatably by the gear rotor 4 as both endportions of the rotational axis 881 are inserted into the two rotationalaxis insert slots 481, respectively.

[0420] The window 48 and the rotational axis insert slots 481 areprovided along the circumferential direction of the gear rotor 4 to forman elongate arc. The roller 88 is allowed to move along thecircumferential direction of the gear rotor 4 within the window 48.According to these arrangements, the roller 88 is allowed to movebetween the position in close proximity to the roller 87 (the stateshown in FIG. 31) and the position at the opposite side with respect tothe roller 87 with the center of rotation of the gear rotor 4, that is,the rotor rotational axis 861, in between (not shown).

[0421] Because the tube 100 or a touching portion 862 described belowconstantly touches the lower sides of the rollers 87 and 88, therotational axes 871 and 881 will never come off from the rotational axisinsert slots 471 and 481, respectively.

[0422] The roller 88 is provided with a regulating member 89. As shownin FIG. 31, the regulating member 89 is mounted rotatably about therotor rotational axis 861. Also, as shown in FIG. 33, the regulatingmember 89 includes two regulating plates 891 that can touch the roller88 from both sides of the gear rotor 4 in the circumferential direction,respectively, and the roller 88 is inserted between the two regulatingplates 891. Regulation by the regulating plates 891 allows the roller 88to maintain the orientation such that the rotational axis 881 intersectswith the rotor rotational axis 861 at nearly right angles.

[0423] When the roller 88 moves along the window 48, the regulatingmember 89 rotates with respect to the gear rotor 4 in association. As aresult, the roller 88 moves with respect to the gear rotor 4 whilemaintaining the orientation such that the rotational axis 881 intersectswith the rotor rotational axis 861 at nearly right angles.

[0424] With the tube pump 1P arranged as above, by brining the rollers87 and 88 in a state that the latter is moved in close proximity to theformer as shown in FIG. 31 while the tube pump is not in use, there canbe obtained a state that neither the roller 87 nor the roller 88 ispressurizing the arc portion 103 of the tube 100. Consequently, as withthe eleventh through thirteenth embodiments above, it is possible toprevent the tube 100 from having a flattening habit or being blocked dueto adhesion of the inner wall while the tube pump is not in use.

[0425] When the gear rotor 4 starts to rotate in the state shown in FIG.31, the roller 87 starts to revolve about the rotor rotational axis 861.On the other hand, the roller 88 remains at the same position withrespect to the main body 86, and moves with respect to the gear rotor 4in the circumferential direction along the window 48 as indicated by anarrow of FIG. 31.

[0426] When the gear rotor 4 rotates until rear end faces 482 of therotational axis insert slots 481 touch the rotational axis 881, therotational axis 881 is pressed by the rear end faces 482, which causesthe roller 88 to start revolving.

[0427] Thereafter, the rollers 87 and 88 are brought into a state thatthey are placed along the circumferential direction of the gear rotor 4at equiangular intervals, that is, at intervals of 180°, whereby atleast one of the rollers 87 and 88 pressurizes the arc portion 103 ofthe tube 100 at a portion thereof to be sealed.

[0428] In the present embodiment, each of the rotational axes 871 and881 of the rollers 87 and 88 is aligned substantially in parallel withthe rotor main body 41 of the gear rotor 4, which is advantageousparticularly in reducing the thickness of the entire tube pump 1P. Also,by mounting the rollers 87 and 88 so that they are inserted into thewindows 47 and 48, respectively, there can be offered a furtheradvantage in reducing the thickness.

[0429] Also, the main body 86 is provided with the touching portion 862that touches the roller 87 or 88 (the roller 88 in FIG. 32) whichever ispresent at a position for not pressurizing the arc portion 103 of thetube 100. By providing the touching portion 862, there can be offered anadvantage as follows.

[0430] The gear rotor 4 receives a force such that tilts the gear rotor4 due to a reactive force from the arc portion 103 of the tube 100 thatthe roller 87 or 88 (the roller 87 in FIG. 32) pressurizes at a portionthereof to be sealed. In other words, in FIG. 32, this force acts on thegear rotor 4 such that the gear rotor 4 tilts downward to the left. Atthis point, in the present embodiment, the roller 87 or 88 touches thetouching portion 862, which prevents the gear rotor 4 from tilting,thereby allowing the gear rotor 4 to rotate more smoothly in a reliablemanner. Also, the roller 87 or 88, whichever is pressurizing the tube100, will not be lifted up, thereby making it possible to pressurize thearc portion 103 of the tube 100 at a portion thereof to be sealed in areliable manner. Also, a change in a reactive force associated with thepressurizing of the tube 100 is lessened, and therefore, a change in therotational loading or a change in the rotational speed of the gear rotor4 is reduced, which stabilizes a quantity of discharge.

[0431] In the present embodiment, one oscillator 6 is provided; however,in the present invention, more than one oscillator 6 may be provided.

[0432] The above description described the illustrated first throughfourteenth embodiments of the tube pump of the present invention. Itshould be appreciated, however, that two or more characteristics of thefirst through fourteenth embodiments can be combined arbitrarily in thepresent invention.

[0433] Also, in the present invention, the minor diameter of the tube100 can be anything from small to large. For example, a tube having theminor diameter of approximately 0.1 to 20 mm can be used, and thepresent invention is particularly suitable to a tube pump using asmall-diameter tube having the minor diameter of approximately 0.2 to 2mm.

[0434] Also, a quantity of discharge, that is, a flow rate, of the tubepump of the present invention is not especially limited, and it can beapproximately 0.01 to 600 mL/min. However, the present invention isparticularly suitable to a fluid feeding pump with a small quantity ofdischarge of approximately 30 mL/min. or less.

[0435] It is needless to say that the tube pump of the present inventionmay feed a fluid intermittently, that is, it may reduce a quantity ofdischarge to 0 temporarily. In this case, the value for the quantity ofdischarge specified above means a value while the fluid is being fed,that is, while the rotor is rotating.

[0436] Also, the present invention is not limited to the illustratedembodiments above, and each component forming the tube pump can bereplaced with an arbitrary arrangement that can function equivalently.

[0437] For example, in the present invention, the shape and thearrangement of the oscillator are not limited to the arrangements shownin the drawings, and any oscillator capable of driving the driven memberis available. For example, the oscillator may have one piezoelectricelement, omit the reinforcing plate, or have a shape such that the widththereof decreases gradually toward the portion touching the drivenmember.

[0438] Also, the oscillator may be able to rotate the rotor in both thenormal and reverse rotational directions, that is, to switch the fluidfeeding directions, by changing the oscillation style thereof dependingon how a current is passed through the same.

[0439] Also, in the present invention, as with the eleventh throughfourteenth embodiments above, at least one of a plurality of thepressurizing portions may be allowed to move with respect to the rotor.Alternatively, in the present invention, all the plurality ofpressurizing portions may be allowed to move with respect to the rotor.In these cases, means for regulating the movable range of thepressurizing portion(s) movable with respect to the rotor is not limitedto a slot or a window formed in the rotor, and can be any means. Forexample, it may be arranged so as to regulate the movable range of thepressurizing portion(s) with a protrusion or a convex portion formed inthe rotor.

[0440] As has been described, according to the present invention, byrotating the rotor with the oscillator, it is possible to reduce thesize, particularly the thickness of the entire tube pump.

[0441] Also, the structure can be simpler, and therefore, it is possibleto save the manufacturing costs.

[0442] Also, because no typical motor is used, electromagnetic noisesare none at all or minimal, if any, so that it is possible to eliminateadverse effects on the peripheral equipment.

[0443] Also, it is possible to prevent unwanted backflow of a fluidwithin the tube.

[0444] Also, in a case where the driven member is formed integrally withor fixed to the rotor, not only can the size and the thickness befurther reduced, but also the structure can be extremely simple.

[0445] Also, in a case where a plate member is provided in closeproximity to the tube so that the tube is pressurized at a portionthereof to be sealed through the plate member, deterioration of ordamages on the tube can be prevented, thereby making it possible toextend the lifespan thereof.

[0446] Also, in a case where at least one of a plurality of thepressurizing portions is allowed to move with respect to the rotor, itis possible to prevent the tube from having a flattening habit or beinglocked due to adhesion of the inner wall while the tube pump is not inuse. Hence, it is possible to prevent adverse effects as follows:deterioration takes place at the segment having a flattening habit; aquantity of discharge from the tube pump becomes unstable; and a desiredquantity of discharge cannot be obtained.

[0447] The entire disclosures of Japanese Application Nos. 2001-218794filed Jul. 18, 2001, 2001-235396, filed Aug. 2, 2001 and 2001-2056 filedAug. 30, 2001 are incorporated by reference.

What is claimed is:
 1. A tube pump comprising: a main body having anattachment portion to which an elastic tube is attached; a rotor mountedrotatably with respect to the main body; a plurality of pressurizingportions, operably associated with the rotor, adapted to pressurize asegment of the tube; a driven member adapted to move in association withthe rotor; and at least one oscillator located so as to touch the drivenmember and having a piezoelectric element, wherein the oscillatoroscillates when an alternating current voltage is applied to thepiezoelectric element and drives the driven member by repetitivelyapplying a force to the driven member by means of oscillations, therebyrotating the rotor.
 2. The tube pump according to claim 1, wherein thedriven member is formed integrally with or fixed to the rotor.
 3. Thetube pump according to claim 2, wherein the oscillator is located so asto touch the driven member along a direction of a rotational axis of therotor.
 4. The tube pump according to claim 2, wherein the oscillator islocated so as to touch the driven member along a radius direction of therotor.
 5. The tube pump according to claim 4, wherein the oscillator islocated so as to touch the driven member from an outer circumferenceside of the rotor.
 6. The tube pump according to claim 4, wherein theoscillator is located so as to touch the driven member from an innercircumference side of the rotor.
 7. The tube pump according to claim 1,wherein the driven member rotates the rotor through a rotational forcetransmission mechanism.
 8. The tube pump according to claim 7, whereinthe rotational force transmission mechanism is a speed changing unit. 9.The tube pump according to claim 1, wherein the oscillator ispositioned, almost entirely, on an inside of an outermost radius of therotor.
 10. The tube pump according to claim 1, wherein the oscillator ispositioned, almost entirely, within a space as thick as the rotor in adirection of a rotational axis of the rotor.
 11. The tube pump accordingto claim 1, wherein the driven member is provided with a slot, and theoscillator touches an inner face of the slot.
 12. The tube pumpaccording to claim 1, wherein the oscillator is of a shape having alonger direction and a shorter direction.
 13. The tube pump according toclaim 12, wherein an end portion of the oscillator in a length directiontouches the driven member.
 14. The tube pump according to claim 1,wherein the oscillator is shaped like a plate.
 15. The tube pumpaccording to claim 14, wherein the oscillator is essentially shaped likea rectangle.
 16. The tube pump according to claim 14, wherein theoscillator is located in an orientation substantially in parallel withthe rotor.
 17. The tube pump according to claim 1, further comprising anarm portion provided so as to protrude from the oscillator, wherein theoscillator is supported by the arm portion.
 18. The tube pump accordingto claim 1, wherein more than one oscillator is provided.
 19. The tubepump according to claim 1, wherein the pressurizing portions areprovided immovably with respect to the rotor.
 20. The tube pumpaccording to claim 1, wherein the pressurizing portions are providedrotatably with respect to the rotor.
 21. The tube pump according toclaim 20, wherein the pressurizing portions are rollers supportedrotatably about their respective rotational axes in a directionsubstantially along a rotational axis of the rotor.
 22. The tube pumpaccording to claim 20, wherein the pressurizing portions are rollerssupported rotatably about their respective rotational axes in adirection intersecting with a rotational axis of the rotor at nearlyright angles.
 23. The tube pump according to claim 20, wherein thepressurizing portions are balls rotatable in an arbitrary direction. 24.The tube pump according to claim 1, wherein the pressurizing portionspressurize the tube at a portion thereof to be sealed along a radiusdirection of the rotor.
 25. The tube pump according to claim 1, whereinthe pressurizing portions pressurize the tube at a portion thereof to besealed along a direction of a rotational axis of the rotor.
 26. The tubepump according to claim 1, wherein an arc portion of the tube attachedto the attachment portion is positioned on an inside of an outermostradius of the rotor.
 27. The tube pump according to claim 26, whereinthe main body includes a touching portion for touching any of thepressurizing portions present at a tube non-pressurizing position. 28.The tube pump according to claim 1, wherein the main body supports therotor from one side.
 29. The tube pump according to claim 1, furthercomprising a flexible plate member provided in close proximity to thetube attached to the attachment portion, wherein the pressurizingportions pressurize the segment of the tube at a portion thereof to besealed through the plate member.
 30. The tube pump according to claim29, wherein the plate member is provided essentially across the segmentof the tube attached to the attachment portion pressurized at a portionthereof to be sealed by the pressurizing portions.
 31. The tube pumpaccording to claim 29, wherein the plate member is provided in adisplaceable manner in a thickness direction thereof.
 32. The tube pumpaccording to claim 29, wherein the plate member is provided so as not tobe displaced in an in-plane direction thereof.
 33. The tube pumpaccording to claim 29, wherein the plate member is provided in adetachable/attachable manner with respect to the main body.
 34. The tubepump according to claim 29, further comprising displacement quantityregulating means for regulating the plate member so as not to bedisplaced over a certain limit.
 35. The tube pump according to claim 1,wherein at least one of the plurality of pressurizing portions isallowed to move with respect to the rotor in a predetermined movablerange.
 36. The tube pump according to claim 35, wherein the plurality ofpressurizing portions are adapted to operate into a first state thatnone of the plurality of pressurizing portions is pressurizing the tubewhile the rotor is at rest, and when the rotor starts to rotate, themovable pressurizing portion moves relatively with respect to the rotorwithin the movable range, so that, in a steady rotation state of therotor, the plurality of pressurizing portions are adapted to operate ina second state that the plurality of pressurizing portions are placed atpositions where at least one of the plurality of pressurizing portionspressurizes the tube at portions thereof to be sealed regardless of arotational position of the rotor.
 37. The tube pump according to claim35, wherein the movable pressurizing portion is adapted to move in acircumferential direction of the rotor within at least a part of themovable range.
 38. The tube pump according to claim 35, wherein theplurality of pressurizing portions are placed along a circumferentialdirection of the rotor at nearly equiangular intervals in a steadyrotation state of the rotor.
 39. The tube pump according to claim 35,wherein the movable pressurizing portion is adapted to move along a slotor a window formed in the rotor.
 40. The tube pump according to claim35, wherein the pressurizing portions are convex portions protrudingfrom the rotor.
 41. The tube pump according to claim 35, wherein: thepressurizing portions are rollers rotatable about their respectiverotational axes in a direction intersecting with a rotational axis ofthe rotor at nearly right angles; and the movable roller is providedwith a regulating member for regulating an orientation of the movableroller so that the rotational axis of the movable roller intersects withthe rotational axis of the rotor at nearly right angles.
 42. The tubepump according to claim 35, wherein: the pressurizing portions arerollers rotatable about their respective rotational axes in a directionsubstantially along a rotational axis of the rotor; the tube pumpfurther comprises, a pressure-applying rotor mounted coaxially with therotor, and a pressing portion, operably associated with the rotor, forpressing the movable roller in a rotational direction of the rotor; andthe movable roller is not supported by the rotor, and in a steadyrotation state of the rotor, the movable roller rotates while touchingthe pressure-applying rotor and the pressing portion.